Experimental Biology and Medicine

In the effort to find an objective criterion of heart failure, the “Q-T” intervals in the electrocardiograms of 155 patients with heart failure have been measured previous to the administration of any drug. The results of Li and Cheer 1 on 178 normal Chinese subjects were available for comparison. The accompanying table gives the data in summary form. “K” is a constant in the formula, S = K√C, in which “S” is the “Q-T” interval in seconds, and “C” the cycle length in seconds. “K” is therefore a measure of the deviation of the “Q-T” interval relative to the cycle length, and may indicate the presence or absence of disturbances in the dynamics of the heart.

It will be seen from the table that “K” is greatly increased in the presence of heart failure, irrespective of the etiology. In the complete paper the data will be given full statistical treatment. Further results to be described later indicate that “K” is frequently increased in patients with heart disease who have slight or practically no failure. If the “Q-T” interval of the electrocardiogram be taken to have a relation to the duration of ventricular systole, the increased “K” indicates a disturbance of cardiac dynamics which might well be found before clinical evidence of failure is available.

Although it is generally believed that egg albumin is a capillarilly active substance, contradictory statements are often found in literature. According to Clark and Mann 1 egg albumin increases the surface tension of water in very dilute solutions but lowers it in more concentrated solutions. It is impossible to draw any conclusion from the works of early investigators because most of them did not pay any attention to the reaction of the solution which is an important factor as shown by St. Johnston 2 and qualitatively by Bottazzi. 3 The latter found the minimum surface tension to be at the isoelectric point, while the former showed the reverse to be the case. The present study deals with the relation between surface tension and the hydrogen ion concentration of egg albumin solutions together with an approximate calculation of the cross-sectional area of the egg albumin molecule.

As we are interested in the equilibrium surface tension, the drop weight method as recommended by Harkins and Brown 4 was adopted, the only modification being that the liquid was pushed over instead of being sucked through the capillary. A necessary condition in this static method is that sufficient time must be allowed for the surface to reach equilibrium. It is well known from the work of Du Noüy 5 and others that the surface tension of a freshly prepared egg albumin solution decreases on standing to a constant value. For the most dilute solutions we used, more than an hour must be allowed to reach equilibrium, while with more concentrated solutions 15-20 minutes will suffice. Egg albumin was recrystallized 3 times from ammonium sulphate solution and dialyzed until no ammonia or sulphate could be detected.

It is a well recognized fact that many patients with hyperthyroidism have disturbances of their cardiovascular system. With the increased demand for oxygen some compensatory mechanism must be at work in order to supply the needs of the tissues. The cardiac output and the velocity of blood flow have been repeatedly shown to be increased, and as a rule, this increase is in direct proportion to the basal metabolic rate. 1 , 2 In the opposite condition, myxedema, Thompson 3 described a reduction in the blood volume and demonstrated its return to normal after the institution of thyroid treatment. Blotner, Fitz and Murphy 4 also observed a correlation between the basal metabolic rate and the total blood count expressed in corpuscles per square meter of surface area. The present report deals with the blood volume findings in individuals suffering from hyperthyroidism, before and after subtotal thyroidectomy.

The series studied consisted of 17 cases of exophthalmic goiter and one of toxic adenoma.∗ The total blood volume was measured by the carbon monoxide method. 5 All the determinations were made in the afternoon about 3 hours after the noon meal. Patients with fever and organic lesions of the heart were excluded. The results are expressed in cc. of blood per kg. of body weight. The minimum blood volume was 58 cc. per kg. and the maximum, 115 cc., with an average volume of 77.3 cc. The average total blood volume in normal individuals studied with the same method was 66.6 cc. (6)

The blood volume of 14 patients was again determined after their basal metabolism returned to normal following subtotal thyroidectomy. The time between the operation and the determination varied from 10 days to 5 months, and some patients had repeated measurements.

In the course of a certain study on hemoglobin it was necessary to mix thoroughly the solution to be analysed with the reagent before evacuation and extraction. As this could not be done in Van Slyke's apparatus, 1 we have devised a new form of the gas burette which, besides serving our special purpose, possesses certain advantages over the form now generally used.

The principal feature of the apparatus (Fig. 1) is that 2 chambers are used instead of one. The extraction is carried out in one chamber (A) while the gas is measured in another (B).

The new apparatus is used essentially in the same way as Van Slyke's. The apparatus is first rinsed with H₂O, and both chambers, including the cock spaces, are completely filled with mercury. The solutions are then introduced into chamber A and the extraction is carried out as usual. On account of the high density of mercury it is desirable to evacuate chamber B also before shaking the apparatus. When the extraction is finished the upper cock is turned to connect A and B. If the pressure in A is high, the mercury in cock space b and above it is pushed over into B. If this does not happen when the cock is opened, shake the apparatus for a few seconds. Mercury is admitted into A and the solution is brought just to the top of A or to a mark slightly above the cock space b—according to how the chamber B has been graduated. The lower cock is then turned to connect B to the manometer and the reading of the pressure is taken in the usual manner at 2, 1 or 0.5 cc.

Attention has already been called to the fact 1 that Cajal's uraniumsilver method, devised primarily to demonstrate the Golgi apparatus, occasionally stains mitochondria. We are not aware of any critical test on record made to determine whether or not this method, without the part of silver-nitrate impregnation, is adaptable to the demonstration of mitochondria. In the course of our studies on the effects of heavy metallic salts upon cell structures, we have had occasion to use Cajal's “uranium-formalin fluid” as a general fixative. Various tissues of frog, white mouse, and guinea-pig were fixed in this fluid for 10 hours. After a quick wash in distilled water, the pieces were dehydrated and embedded in paraffin, and sections were stained with fuchsin and methyl green. In all cases, it was found that the mitochondria had been well fixed and excellently differentiated but mostly in cells near the surface of the block, the deeper-lying ones being less affected. This was evidently due to the poor penetration of the fixative. An effort was made therefore to improve this effect by adding to the fixing fluid a small quantity of glacial acetic acid. The results were so satisfactory that this method seems to be in certain respects better than others so far available.

Further, we experimented on a mixture of this “uranium-formalin fluid” with fat solvents such as alcohol of 80% to 100% strength, ether and chloroform in various proportions with a view to testing their solubility upon mitochondria. It was surprising to find that in tissues, notably pancreas, liver, kidney, gastric and intestinal glands, the mitochondria remain either in long filaments or short rods, distributed abundantly in the superficial as well as in the deeper-lying cells.

The use of a mixture of ephedrine and homatropine as a mydriatic for diagnostic purposes has been recommended by Geppert and Groenouw. 1 They found that a small amount of homatropine enhances the mydriatic effect of ephedrine, and the time at which mydriasis passes off is practically equal to ephedrine. Later this observation was repeated by many clinicians 2 using “Mydrin”, which is a mixture of ephedrine and homatropine. By comparative experiments with ephedrine and homatropine we have further observed the mydriatic effect of this mixture.

White rabbits were used. The horizontal diameter of the pupil was measured in a dark-room, the source of light being at a constant distance. The change of pupil in strong light was also observed at a constant distance from a lamp. The drugs were applied to the conjunctival sac. A great number of preliminary experiments showed that the pupil on both sides responded to the drugs at practically the same rate and strength. The mixture of ephedrine and homatropine was in the proportion of one hundredth part of the latter to one part of the former substance.

In 6 experiments the mydriatic effect of a small dose of ephedrine on the homatropinized eye was observed. A small amount of homatropine such as one drop of 0.001% to 0.005% solution was applied to the eye on one side (which would produce a dilatation of 1 to 2.5 mm.) and half an hour later one drop of 0.1% to 1% ephedrine solution was applied to the homatropinized eye and also to the eye of the other side. In one case ephedrine (7 mg. per kilo) was injected intravenously. The homatropinized pupil was further dilated by ephedrine but its dilatation was simply due to an additional effect of the mydriatic action of ephedrine and homatropine and was not an augmentation of the homatropine effect.

Since the ingestion of fat results in the inhibition of the secretion of autotransplanted (i. e., completely denervated) gastric pouches (Feng, Hou and Lim 1 ), the mechanism concerned must be a humoral one. It was thought that as fat causes the ejection of bile into the duodenum, the reabsorbed bile (salts) might be the humoral agent, but this has been proved not to be the case (Kosaka and Lim 3 ). The influence of fat on the gall bladder has been shown by Ivy and Oldberg 2 to be due also to a humoral agent. Having a sample of Ivy's gall bladder hormone, viz., cystokinin, on hand, this was tried and found to inhibit gastric secretion in large doses (5 gm. per kg.). An attempt was therefore made to recover the gastric inhibitory agent from the intestine.

The upper small intestine of dogs (under ether or decerebrate) was ligatured in segments about 10 cm. long, and 50 cc. of olive oil introduced into alternate segments. After one hour, the intestine was removed and the mucosa exposed and unexposed to oil separately scraped off and extracted with N/10 HCl at a relatively low temperature (about 60°C.). Extracts have also been made simply with saline. Extracts from mucosa exposed to oil inhibit gastric secretion to a meat meal, when injected either intravenously or subcutaneously into Heidenhain-pouch dogs, the degree of inhibition produceable being comparable with that caused by the oral ingestion of fat (see Table I). Similar doses of the saline extract appear to have no effect on either the pancreatic or biliary secretion and do not depress the blood pressure. Further, when these extracts are heated to 80-100°C. for 10 minutes, the inhibitory effect is removed, and if HCl is added before heating, a gastric stimulating action is frequently obtained.

It was reported 1 earlier that white flaming carbon arc and quartz mercury vapor energy had little or no effect on a milk anemia in rats. Most of the observations were made with the carbon arc and continuation of the work has demonstrated a definite effect by the mercury arc, as evidenced by number and size of reds and hemoglobin content and saturation. Doses of about 10 minutes daily at a distance of 35 cm. seem optimal, larger doses showing a tendency to depress growth and produce burns. Doses of less than 5 minutes were practically without effect. Again no definite results have been obtained following exposure to the energy emitted by “Sunshine” carbons.

Anemia was produced in 18 adult dogs on a standard diet by subcutaneous injection of acetylphenylhydrazine (pyrodin). Eight animals were irradiated with the flaming carbon arc (Pan-Ray-Arc burning “Sunshine” carbons), 3 with the quartz mercury vapor lamp (Cooper-Hewitt), and the remainder served as controls.

Although there were variations in the reactions to pyrodin and to radiation the regeneration of the red cells was unquestionably faster in the irradiated group. The average count of the control group 23 days after the injection and 15 days after the lowest anemic level was 71% normal. The average value for the same number of irradiated animals that developed a comparable degree of anemia was 85% normal. The carbon and mercury arcs were equally effective. The difference in hemoglobin regeneration is not so marked, the average values 15 days after the lowest anemic level being 77% and 82% normal in the control and irradiated animals respectively. This relatively greater response of the red cells to irradiation was previously reported in studies on hemorrhagic anemia. No significant differences in reticulocytes, whites, platelets and red cell fragility were observed. The development of a tolerance to the drug on repeated injections invalidated attempts to use the same animal for control and irradiation periods.

A review of the literature reveals that a vitamin deficient diet fed to animals will alter the motility of their gastro-intestinal tract, and is also capable of producing in their intestines marked pathological changes. Most of these observations appertaining to the motility, however, were made by methods other than with the Roentgen rays and in the few instances wherein it was employed, the skiagraphic method was used with unsatisfactory results.

In order that experimental observations upon animals may have a practical application to man, it is necessary to utilize animals whose diet is very much of the same nature as that of the human species, and their gastro-intestinal tract must bear a close resemblance to that of primates. In the rat we have an animal that will ideally serve this purpose, better in fact than herbivorous or graminivorous mammals.

A comparative study by means of frequent fluoroscopic observations was made on the motility of the gastro-intestinal tract of rats fed diets deficient in vitamin B, vitamin D and also a diet deficient in vitamins A and D with a balanced mineral content. These studies were undertaken principally to ascertain the effect of deficient vitamin A and D diet with adequate mineral balance, upon the motility of the gastro-intestinal tract of rats.

Seventy rats were used. Twelve were fed a deficient vitamin B diet, 14 a deficient vitamin D diet with an unbalanced mineral content, 17 a diet deficient in vitamins A and D but with an adequate mineral balance and 27 normal rats served as controls. After the rats were fasted for 48 hours and water withheld during the last 24 hours of fasting they were fed, in separate cages, a meal consisting of 5 gm. of barium sulphate and 5 cc. of buttermilk.

The comparative permanence of electrocardiographic abnormalities, especially bundle branch block, once established is an admitted maxim. The more promising possibility of the transient nature of such disturbances is usually not considered. In experimental work on conduction in the heart of the dog, Wilson and I 1 were impressed by the fact that relatively light pressure exerted over one of the main branches of the His'bundle would produce bundle branch block from which there was complete recovery within a few minutes and a return to an absolutely normal intraventricular conduction time which was recorded.

Lewis had observed a patient with transient bundle branch block as early as 1913. There have been 9 other instances recorded in the literature which at one examination presented defective conduction while at another later examination the normal intraventricular conduction was recorded and vice versa. In none of these instances, however, was there any record of a transition of a sudden nature. In fact, in most of them there is a suggestion of a gradual transition. This condition is not so uncommon since 5 similar cases have come under my observation.

Three additional cases of unusual interest and importance were encountered. These were extraordinarily unique in that the sudden transitions were recorded electrocardiographically. In each one of these instances the transition was within one beat and was from complete bundle branch block to absolutely normal intraventricular conduction. These observations constitute clinical corroboration of our experimental findings and of the pathological findings of Cohn and Lewis. 2 There seems to be evidence sufficient that temporary mechanisms and functional changes in the conductive system in the diseased human heart as well as in the normal dog heart may induce bundle branch block.

Subarachnoid spinal adhesions may at times produce clinical symptoms. Such a case has been observed by us in which following a laminectomy for paraplegia numerous adhesions of the spinal subarachnoid space were found. These adhesions were divided, but as adhesions involving all serous membranes are apt to recur, the possibility of a recurrence of these subarachnoid adhesions was considered. As Herrmann and Musser, 1 and Ochsner and Herrmann 2 had successfully prevented the recurrence of adhesions in the pericardial cavity and Ochsner and Mason 3 in the peritoneal cavity experimentally by the use of digestants, it was thought possible that such procedures might be employed in the prevention of the recurrence of spinal subarachnoid adhesions.

Our purpose in this study was to produce subarachnoid adhesions by introducing an irritant into the spinal subarachnoid space in the lower thoracic region of dogs, later to divide these adhesions, and to attempt to prevent their reformation by introducing a digestion solution. We have been able to find no record of a previous attempt of this kind, although Dr. E. R. Schmidt, of the University of Wisconsin, has employed a digestant in the subarachnoid space in one case in order to attempt to prevent the reformation of adhesions.

The experimental animals employed were dogs. An attempt was made to inject the irritant into the spinal subarachnoid space by spinal puncture, but because of the difficulty encountered in performing a lumbar puncture, this method was abandoned. A formal laminectomy was employed in the remainder of the animals, and the irritant was injected into the subarachnoid space by means of a syringe and cannula. The animals were prepared in the usual manner; ether was used as the anesthetic agent.

Four apparently healthy chickens weighing approximately one kilo each were used in this experiment. Jamaica ginger obtained from a community where there were many patients with peripheral neuritis was used. Two of the chickens received daily doses of 2 cc. fluid extract of ginger and the other 2 received an equal amount of 83% ethyl alcohol. The chickens were kept in a cage out of doors and their diet consisted of cracked corn and oats. The chickens receiving the alcohol were accidentally killed 10 days after beginning the experiment.

Thirty-eight days after receiving the first dose of ginger and after each chicken had been given a total of 70 cc. there were no signs of muscular weakness. There had been some loss of weight during this time. On the thirty-ninth day the chickens exhibited slight motor weakness and loss of coordinating power in both extremities. Feeding ginger was discontinued at this time. During the next 2 days there was a progressive motor weakness and the difficulty in walking or standing was marked. Control of the feet was completely lost and the toes were turned under the feet when an attempt was made to walk. The legs rather than the feet were used to support the body when resting. There was apparently no sensory disturbance of the extremities and no edema was observed.

A thick suspension of rice polishings was given through a tube when the paralysis was first observed and daily thereafter for a period of 5 days without any improvement. One of the chickens died 8 days after the onset of the paralysis. Sections of the nerve trunks have not yet been examined. Motion pictures were made to demonstrate the paralysis.

The practice of heating serum to 56°C. for 30 or more minutes unquestionably increases the precipitating ability of blood serum from syphilitics for the saline suspensions of lipoid-cholesterin antigens now used in the precipitin test for syphilis. Insistence upon the use of “inactivated” serum in such precipitin tests apparently began in 1918 by Sachs and Georgi, 1 and was followed by Meinicke in his third modification in 1919, 2 and by Dreyer and Ward 3 in 1921, and Kahn 4 in 1922.

It is rather paradoxical that heating of serum should lower the “specific” antibody titre utilized in the Wassermann reaction by 75%, as shown in the now classical researches of Noguchi, 5 and simultaneously increase the precipitin titre by 8 times (from 10 to 80 Kahn units) as was recently shown by Kurtz 6 in Kahn's laboratory. The explanation advanced by Dreyer 3 of a complex antisyphilitic antibody, composed of a thermostabile precipitin coupled to a thermolabile substance which inhibits precipitins and favors complement fixation, is rather theoretical to say the least.

Kurtz quotes an apparently unpublished opinion by Nishio, a worker in Kahn's laboratory, “that the function of heating is to reduce the protective properties of the serum albumins to precipitation.” This is a most plausible theory. By advancing another purely physical method of increasing the titre of the “specific” precipitin in serum the additional evidence may be sufficient to transfer this phenomenon to terms of a simple biochemical reaction.

Using my modification 7 of Butler's antigen 8 for the slide precipitation test for syphilis I have found that by allowing the serum to dry completely the precipitating action of syphilitic serum is increased to almost identically the same extent as when heated.

Formerly diabetics were regarded as very poor surgical risks. Not only was there fear of infection and poor healing but the effect of a general anesthetic was dreaded. Since the advent of insulin it has been shown that diabetics may be operated upon with almost the same degree of safety as normal individuals. Even in normal persons the administration of general anesthetics may produce an acidosis. The metabolism may be profoundly affected. The post-operative period of vomiting and starvation contribute still further to the threat of acidosis. The administration of a general anesthetic to a diabetic, therefore, has been in the past a matter of no small concern. In spite of this there have been apparently recorded in the literature few definite observations as to the alkali reserve of the blood in diabetics under anesthetics and afterwards. The only 2 references I have been able to find in the insulin era have been those of Rabinowitch 1 and McKittrick and Root. 2 The former gives data as to the pH and CO₂ combining power in 2 diabetics under ether. He does not state whether insulin was used. McKittrick and Root state: “We have used the plasma CO₂ combining power as the best index of acidosis and it is true in 15 cases a reduction in this value occurred as a result of operation, with a return to normal within 24 hours due to the use of insulin and carbohydrate food.” Rabinowitch pointed out: “The finding of a low CO₂ combining power in the plasma does not always necessarily denote acidosis. The lowered CO₂ combining power may be due merely to the increased pulmonary ventilation accompanying anesthetics.

Leonard and his associates (Leonard, 1 Leonard and Frobisher, 2 Hampil 3 ) have demonstrated the bactericidal properties of the acyl and alkyl derivatives of resorcinol and Ratcliffe 4 has shown that the administration of certain of these derivatives to rats not only changes the intestinal flora from a Gram-positive to a Gram-negative type but also is effective in reducing the protozoa in the cecum (Trichomonas spp., Endamoeba muris). Trichomonads in young chicks were also killed on a one per cent N-heptyl resorcinol diet fed for 5 days (Ratcliffe, 1. c.). At the suggestion of Dr. Veader Leonard the writer has made a study of the effect of di-hydranol, a homolog of hexyl resorcinol, on certain intestinal protozoa of man and mammals in New Orleans. The drug has been prepared by Sharp and Dohme of Baltimore and been placed at the writer's disposal through the courtesy of Dr. Leonard.

Structure and properties of di-hydranol. Di-hydranol (2-4-dihydroxy-phenyl n-heptane) is a yellowish crystalline product with the structural formula:

Its taste is at first slightly sweetish, but soon there develops a definite mild acrid pungency, very similar to that of the root of the Indian turnip, Arisaema atrorubens, to be followed later by a mild numbness of the tongue. The drug is only slightly soluble in water. Hampil (1. c.) found the series to which this group belongs to be more bactericidal in alkaline solutions, presumably due to their greater solubility in this medium. In concentrated crystalline form it is too irritating for the human stomach but in olive oil, in which it is highly soluble, this difficulty is entirely obviated. Almost all of the drug is excreted by the bowel; its presence in the urine of a patient taking the drug in olive oil can be detected only by the most delicate technic. Its toxicity is clinically negligible.

1. By utilizing a technic whereby muco-sanguinous exudate f rom active cases of amebic colitis in dogs is injected per anum into the distal portion of the ileum, infection corresponding to spontaneous amebiasis in this host has been produced in 13 out of 14 dogs (93%), ranging in age from 2 months to 4 years. 2. The incubation period, as determined by the presence of active Endanzoeba histolytica in mucus withdrawn directly from the cecum, has ranged from one to 23 days, with the largest number of findings on the second day. 3. Acute cases, probably complicated by bacteremia, terminate with death in about 2 weeks. Chronic cases and one spontaneous recovery have also been observed. Carrier cases, with the passing of cysts in the stools, apparently do not develop in dogs. 4. The cecum is the primary seat of infection with E. histolytica in the dog. 5. The dog apparently receives its amebic infection from man but due to the failure to produce cysts the infection apparently cannot be transferred in nature from dog to dog or from dog to man.

1. The immunity produced by a single course of 3 doses of typhoid vaccine may not be as great as usually believed. A second inoculation probably ought to be given some weeks or months after the first. 2. The Widal Reaction is much less reliable as a test for typhoid fever among those who have had more than one inoculation with vaccine than among those who have had only a single inoculation.

In a previous report 1 we observed an increase in toxicity of bile salts∗ injected intraperitoneally into the white mouse when sodium citrate was added. In the present study the effects of varying dilutions of bile salts and sodium citrate on human blood cells in vitro have been observed.

When bile salts are added to red blood cells of different individuals and allowed to stand at room temperature for 18 hours, hemolysis occurs through dilutions of 1:200 to 1:6400. The bloods of 100 undiagnosed individuals were examined in order to determine their susceptibility to bile salt hemolysis. The large variation in ability of bile salts to hemolyse different bloods is independent of changes due to age of cells, and independent of the temperature and humidity under which the cells are kept.

When sodium citrate is added to bile salts, hemolysis of red cells takes place in higher dilutions of the bile salts than when the bile salts per se are employed and the dilution at which hemolysis takes place depends upon the concentration of the sodium citrate added. If concentrations of less than 0.032% (1:3200) of sodium citrate are added there is no increase in the hemolytic power of bile salts; however, as the concentration of sodium citrate added is increased above 0.032% the hemolytic power of the bile salts is likewise increased. For example, if 1% (1:100) sodium citrate is added to the bile salts dilutions, hemolysis takes place in the 1:400 dilution, while if 4% (1:25) sodium citrate is added hemolysis takes place in the 1:1200 dilution of bile salts. We see by these figures the gradual increase in hemolytic power of bile salts produced by addition of sodium citrate from the 0.032 to 1% concentrations and the rapid increase from the 1 to 4% concentrations.

While working upon the relationship of sodium citrate to bile salt hemolysis, interest was aroused in the microscopic picture produced in blood by addition of this sodium salt. As far as has been ascertained the changes observed have not been heretofore described, nor has it been explained in what manner a 30% sodium citrate solution stops hemorrhage when injected intravenously or intramuscularly, whereas the less concentrated solutions (4-10%) act as anti-coagulants when added to blood for transfusion.

In our observations fresh defibrinated blood, serum from clotted blood, citrated blood and blood added to the dilutant from the finger tips were studied. In each case the findings corresponded. The solutions of sodium citrate used varied in dilutions from 0.2 to 50% by weight and in all cases distilled water was used as vehicle. Saline (0.2 to 30%) was run in comparison but findings with this salt were limited to crenation in the hyper and swelling with chromolysis in the hypotonic dilutions.

When blood serum is added to a 20-50% solution of sodium citrate a flocculent, milky precipitate is formed. This redissolves macroscopically on adding more serum. This precipitate also forms in 20-50% sodium citrate solution when serum which has been passed through a Berkefeld filter or has been kept at 55°C. for an hour is added. Positive tests for globulin are obtained from the precipitate, which microscopically appears as a coarse granular material with a tendency to aid in the clumping and enmeshing of red and white blood cells and which when observed under the microscope does not disappear in toto on the addition of more serum. Fragmenting leucocytes are seen in 20-50% dilutions of sodium citrate with thread-like filaments projecting from apparently injured portions of their surface membrane.

Just subsequent to the outbreak of the epidemic of bubonic plague in New Orleans, the occurrence of a concurrent rodent plague was revealed. Every rat trapped, captured or found dead, either from disease or from fumigation, was sent to the Health Department Laboratory for full investigation.

Because of the occurrence of this epizootic, the opportunity for study of approximately 150,000 rats was presented. While engaged in this routine work, we observed that many of the rats presented a peculiar discoloration of the feet. This discoloration occurred in the living trapped rats, as well as those that were dead. The lesion was so striking in appearance that the investigation of its significance seemed justified. A special study of the rats having this discoloration was made and it was noted that, in all instances, these animals were proven to be infected with plague.

Character of Lesion: The color presented is very apparent in the feet of the infected rodent animal and occurs in both extremities; it varies from a pink to a salmon tint. The lesion is clear cut, having a distinct line of demarcation and varies in its extent of distribution. In slight infections, it is confined to the feet alone, covering both the dorsal and plantar aspects, hence the appellation “pink feet” was applied. In more marked infections, the color extends over the entire extremities and, at times, appears upon the abdominal and thoracic walls. The discoloration is not due to petechial hemorrhages such as seen in hog cholera or the hemorrhagic septicemias nor is it analogous to a scarlatina erythema, but rather suggests the tissue discolorations that are seen in carbon monoxide poisoning. It appears that there occurs either some hemolytic change, causing a laked blood aspect or that the hemoglobin is, in some manner, modified and permeates the structure.

In Science for December 23, 1927, Dr. Hugh M. Smith printed a letter relating the existence in Siam of solanaceous plants whose fruits appeared to have a marked effect on the sugar content of the urine of diabetes. The plant supposed to have been used was sent by Dr. A. Kerr from Siam to Kew Gardens, London, from which, in turn, it was sent to Prof. Craib of Aberdeen, Scotland, who described it as a new species, Solanum sanitwongsei, after the late Japanese physician, Dr. Yai S. Sanitwongsei, who first used the solanaceous fruit in treating diabetes. After strenuous efforts Dr. George T. Moore, Director of the Missouri Botanical Gardens, succeeded in getting seeds from the original plant described by Dr. Craib. Dr. Moore very kindly supplied us with ripe fruit grown at the Missouri Botanical Garden, and thus presented the opportunity to study its effect on diabetics.

The fruits resemble small tomatoes, averaging about one centimeter in diameter and become yellow or red when ripe. In Siam, patients were given 3 to 10 with each meal. When they were administered with the food of diabetics, the glycosuria was reported to clear immediately and remain absent for about 20 hours, but return unless the fruits were again taken. The diets, containing large amounts of rice, apparently were not restricted.

In this investigation, patients were given 5 to 7 ripe fruits to eat with each meal. Table I shows they had no appreciable influence on the blood sugar following breakfast in mild diabetics. There was no effect on the glycosuria. The severe diabetics represented in Table II had been in the hospital for less than a week and steady improvement would have been expected with the insulin and dietary regime alone.

1. Sodium salicylate suppresses the allergic dermal reactions of rabbits to filtrates of hemolytic streptococcus. This effect is most definite when sodium salicylate is given before the focus of infection has developed. 2. There is no relation between the presence or absence of this dermal reactivity and the character of the vascular pathology.

Sedimentation of the corpuscles of heparinized blood was determined by noting the extent of fall in glass tubes with an inside diameter of 4 mm. and height of 100 mm. during an interval of 1 hour. The tubes were centrifuged to insure complete sedimentation and the sedimentation index computed as the ratio between the sedimentation observed in 1 hour and the possible maximum extent of sedimentation.

Precipitability of serum protein was determined by adding various amounts of aluminum sulphate, as contained in a unit volume of 1 cc. to 0.2 cc. of unheated blood serum in small tubes. Serum and reagent were mixed and set aside at room temperature for 1 1/2 hours. A heavy flocculent precipitate that settled out, leaving a clear supernatant fluid, was recorded as a positive reaction.

Maximal, minimal and average values for these blood properties as observed in the arterial blood of 20 normal male rabbits, with similar values for total protein, fibrin, globulin and albumin as contained in the plasma are listed in Table I.

Departures from the limits of the normal range in these blood properties were noted upon monthly blood examinations subsequent to experimental tuberculous infection in normal and allergic rabbits. Of 5 animals inoculated (subcutem) with human-type tubercle bacilli 2 exhibited a slight and transitory increase in plasma fibrin. In none of the animals was there observed an acceleration in erythrocyte sedimentation or an increase in serum precipitability.

No change was observed in total protein or in distribution of the various plasma fractions in 11 animals inoculated (intraperitoneally) with bovine-type tubercle bacilli. Increase in erythrocyte sedimentability occurred in 3 animals. Lability of the serum was increased in 3 animals. These increased were not of great magnitude, transient and were co-existent in 1 animal.

To date experimental evidence is lacking that animals may acquire immunity to cestode parasites as a result of periodically injected worm material or extracts of it. In fact the data concerning active immunity to any metazoan parasite are meagre and have only recently been reported.

Cysticerus fasciolaris, in the liver of the rat and mouse, is the larval stage of Taenia taeniaeformis (crassicollis) in the intestine of the cat. Infestation of the rat results from accidental ingestion of the onchospheres in the feces of the cat. These penetrate the intestinal wall of the rat, reach the liver via the portal system, and eventually develop into long strobilate cysticerci in connective tissue cysts of host origin. When ingested by the cat these mature in the intestine.

We have succeeded in immunizing the white rat by periodic injections of dried pulverized worm material as a 1% suspension in 0.1% HCl. Small quantities were injected intraperitoneally at 2 or 3 day intervals, and 5 weeks after the last injection both control and immunized animals were fed equal portions of a uniform suspension of onchospheres by means of a stomach tube. After a period of a month 9 control animals had from 10-42 (average 21.4) cysts, 2-5 mm. in diameter, in the liver; while for the most part the young worms in 9 immunized animals were dead, being represented by small, well-circumscribed spots (usually 1 mm. in diameter) in the liver. The average number of these was 21.1. A few control animals also showed spots (1-12) representing degenerated worms; and a few immunized animals showed, in addition to the necrotic cysts, small numbers of living cysts, usually much smaller in size than those in control animals.

The pathology of acute poliomyelitis in monkeys has recently been described by Hurst 1 with special reference to changes in microglia. The object of the investigations reported here has been to supplement the above by a description of the injured nerve cells which so far in the course of the disease have escaped digestion by neuronophages. Thus certain nuclear changes in ventral horn cells and cells of the medulla have been found to follow or occur simultaneously with the more easily recognized cytoplasmic degeneration which may be profound.

Central nervous system tissues of 33 monkeys dead of poliomyelitis, or sacrificed at various stages during the course of the disease, were fixed in Zenker's fluid and stained with Giemsa for routine work. For comparison the tissues of 10 normal monkeys were available. Fixation has been supplemented by methods of Carnoy, Champy, A. O. B., Regaud, etc., and numerous staining methods have been employed including erythrosin-azur, phloxine-methylene blue, hematoxylin-eosin, phosphotungstic hematoxylin, etc. Sections for study were cut 3 to 5μ in thickness.

Areas of the cord showing lesions typical of acute poliomyelitis contain a number of faintly stained nerve cells. The cytoplasm of these cells is badly damaged and in some instances appears to be lacking. The nucleus, on the other hand, is usually severely altered but retains a nuclear membrane. It may be large and clear, presenting an appearance similar to a nuclear change described by Cowdry and Kitchen, 2 Plate V, Fig. 48, for liver cells, in cases of yellow fever. The nucleolus may be absent, broken up and plastered against the nuclear membrane, or displaced in position and ragged in shape. Usually the nucleus of these cells contains one or more acidophilic-staining bodies (Figs. 1-5), definite in their outline, and measuring from about 0.25μ to 3μ in diameter.

The Cooper-Hewitt lamp, quartz light and x-ray in low voltage cause an activation of the vitamin D and the vitamin A in yeast fed to rats along with a deficient vitamin D and vitamin A ration. The period of exposure of the light in each case varies with the type of light used. The maximum point of activation is found with each light.

In this study 10 healthy male dogs kept under standard conditions of exercise, maintained at a weight that varied less than 5% and fed a constant diet were bled 15 hours post-absorptive over a period of a month, at intervals of 1-16 days. Analyses for total lipid were carried out on 5 cc. samples of plasma according to the methods outlined by Bloor, using also his technique for the colorimetric determination of cholesterol by the Liebermann-Burchard reaction. 1

The reliability of the procedures claimed by Bloor was verified, the total lipid method giving a standard deviation of ±1.4% and the cholesterol ±2.6%. Significant changes in lipid levels were taken as average differences of more than twice the standard deviation, or 5.1%. It was found that the method for phospholipid (1929) was reproducible with a standard deviation of ±4.1% on stock alcohol-ether extracts and on purified petroleum ether solutions of phospholipid, but when applied to the plasma extracts from the dogs under study, low values which could not be duplicated were obtained.

The average standard deviation for 4 post-absorptive determinations of cholesterol was ±6%. The values for the individual dogs varied from 68 mg. % to 118 mg. % with a standard deviation of ±28%.

The total fatty acid levels for the individual animal varied by a standard deviation of ±7%, and the means varied from 205 mg. % to 348 mg. %, with a standard deviation of ±13%.

It is evident that the cholesterol and total fatty acid levels in an individual dog are relatively constant over the period of one month of controlled conditions, ant1 that there may be large differences between one (log atid another. The lowest values for cholesterol and total fatty acid ua-e given by young dogs, and the highest values were obtained from an old dog.

It has been found recently 1 that the glycogen content of the rat gastrocnemius diminishes on an average by 101 mg. % 30 minutes after an epinephrine injection, while the lactic acid content of the muscle increases by only 29 mg. %. Part of the lactic acid formed in muscle diffuses into the blood but even if one allows for this on the basis of the increase in blood lactic acid (which amounted to 21 mg. %), one arrives at a total of only 40 mg. % lactic acid. Hence, 61 mg. % of the muscle glycogen which disappears remains to be accounted for.

Three hours after an epinephrine injection, when the blood lactic acid has returned to the original level, a much larger portion of the disappearing muscle glycogen can be accounted for. 2 The liver glycogen formed from blood lactic acid including that part which is mobilized again, makes up for 83% of the glycogen lost from the muscles. The rest is such a small amount that it might have been oxidized without appreciably affecting the R.Q. which was 0.715 for the 3 hour period after the injection. Since most of the muscle glycogen which remains unaccounted for 30 minutes after the injection eventually (within 3 hours) yields liver glycogen by way of blood lactic acid, it seemed desirable to look for a substance, intermediary between glycogen and lactic acid, which might have accumulated in muscle owing to the fact that the conversion of glycogen into the precursor proceeds more rapidly than the conversion of the latter into lactic acid.

It seems fairly well established that the lactic acid precursor in muscle is a hexose-phosphoric acid ester.

A new technique for making motion pictures of the vocal cords has been developed by the use of a quartz rod as the means of projecting a high intensity illumination within the larynx. The source of light consists of the two filaments of an overvolted automobile bulb. A laryngoscope, illuminating system and viewing finder are attached to a 16 mm. motion picture camera. This combination forms a self-contained, one-man-controlled unit, which permits motion pictures of the cords to be made at the standard rate of 16 frames per second. The field photographed is viewed constantly through the finder by the operator, who controls the spring motor of the camera by the usual release button. The pictures as projected fill the entire screen area. This is a magnification previously unattained under these conditions.

The effect of a meal containing 100 gm. of butter and 50 gm. of olive oil mayonnaise, alone, and with exercise, has been determined in 2 normal and 4 non-diabetic obese subjects.

The metabolism was determined by collection and analysis of the expired air; after determining the basal metabolic rate the subjects were usually exercised while still in the post-absorptive state and before the ingestion of the fat meal; this gave the post-absorptive metabolism both at rest and in exercise. They were then given the 150 gm. of fat and the resting and exercise metabolism was determined, usually once an hour for 7 to 8 hours.

The exercise consisted of having the subject lift the lower extremities, while lying on the back and connected with the spirometer, rhythmically and alternately so as to touch with the toes a board placed a given distance above the foot of the bed. The rhythm was maintained by the use of a metronome which was usually set at about 76 beats per minute, so that a lower extremity was lifted 19 times per minute. This exercise increased the metabolism from 2 to 3 times. The subjects exercised for 2 minutes before collection of the expired air was begun; and this was continued for 5 or 6 minutes, depending on the degree of fatigue produced.

In 2 normal subjects and one of the obese there was a slight initial rise in the resting respiratory quotient following the ingestion of the fat; this was followed by a gradual fall, which, at the end of 6 to 7 hours reached a level lower than the resting quotient.

In 3 of the 4 obese subjects there was a rise in the resting quotient following the fat meal.

We have previously 1 demonstrated that an extract which will definitely prolong the lives and ameliorate the symptoms of adrenal-ectomized cats can be made from the adrenal cortex.

We have proposed the name of cortin 2 for this hormone, which is essential to life.

Heat (80°C. for 5 minutes) destroys it. It is lost upon repeated precipitation with NaCl. Therefore some other method of concentration must be employed.

An extract of any desired concentration can be obtained by extracting the cortex with ethyl ether. After removing the ether in vacuo the residue is extracted with warm 80% alcohol. Chilling precipitates much inactive material. Removal of the alcohol in vacuo is followed by extraction of the residue with water to make the desired concentration, or extraction by alcohol is repeated for further purification.

Completely adrenalectomized cats treated with this extract not only live indefinitely in good condition but are able to meet unusual demands apparently as well as normal animals. They undergo major operations. Wounds heal promptly. They seem to resist infections to which untreated adrenalectomized cats often succumb. One cat had an abortion following the removal of the second adrenal and bled for several days afterward. Yet, by the use of this extract she recovered. Another cat was etherized and thoroughly explored for accessory adrenals 136 days after the removal of the second adrenal, with recovery as prompt as would be expected in a normal cat.

If adrenalectomized cats are given more extract than is necessary to keep them in fair condition they eat more and gain in weight. Blood urea remains within the normal range.

One adrenalectomized cat has been rescued from the final stage of prostration due to an inadequate supply of cortin 3 times by injection of extract.

Charts and tables showing relationships between the urinary reaction and phosphate concentration in short period experiments on subjects taking normal diets and eating a standard meal were prepared. The experimental technique has been described elsewhere. 1 The Bell-Doisy method was used in determining the phosphate concentration. 2 When equal reactions were found on 2 specimens of urine obtained at about the same time the actual pH values were usually fairly low, but there was a second, smaller group in which they were more alkaline. The reactions of relatively few specimens fell between pH values of 6.0 and 7.0. The authors believe that the former, larger group, probably represents a true physiological constancy of the reaction, while the smaller one where the reaction is more alkaline they think frequently contains instances in which those changes in the reaction of urine which take place after a specimen has been voided 3 have taken place under approximately constant conditions, and have produced a constancy of reaction which may have little physiological significance. The phosphate concentration was much higher in the more acid than in the more alkaline group.

Further study of the material brought out the following points: 1, when the reactions of 2 specimens of urine obtained from the same patient differed by 0.2 pH or less the average of the means of the phosphate concentration in the urine was about 20% higher than in the whole series; 2, when the reactions of 2 specimens differed by more than 2.0 pH the average of the means was 50% lower than in the series considered as a whole; 3, when the mean phosphate concentration was high very few specimens showed differences in reaction which were greater than 0.2 pH; 4, when the mean phosphate concentration was low about half of the specimens, even from patients with achlorhydria, showed differences in reaction greater than 0.2 pH; 5, the average mean pH was lower when the phosphate concentration was low than when it was high; 6, in many individual experiments there was little or no correlation between changes in reaction and in phosphate concentration; 7, the average phosphate concentration was higher in achlorhydria, possibly due to the small hourly volume of urine excreted, than it was in a short control series.

Infections in the floor of the mouth may extend into the deep facial planes of the neck and produce a cellulitis which has a decided tendency to terminate in gangrene or abscess formation. Ludwig originally described the condition as a gangrenous induration of the neck; Vincent refers to the disease as a foetid para-buccal abscess. The primary focus occurs about the teeth in most instances (Muckleston, 1 Van Wagenen and Costello, 2 Ashhurst 3 ). These observers, among others recovered an aerobic streptococcus from the cervical lesion, more rarely staphylococci or other aerobic organisms, which they regarded as presumably the causal agent. However, no reference is made to anaerobic studies. Melchoir 4 found fusiform bacilli and cocci in 4 cases; fusiform bacilli alone in one case; spirochetes, fusiform bacilli and cocci in another case. More recently, Hansen∗ told me he observed a fatal case of Ludwig's angina in which he found fusiform bacilli and spirochetes in large numbers.

It has been demonstrated that local lesions about the teeth generally harbor fuso-spirochetal organisms. These organisms produce a foul abscess or gangrene when introduced into the tissues of animals. 5 , 6 , 7 It therefore seemed reasonable to infer that Ludwig's angina might be due to a fuso-spirochetal infection.

The scrapings from the teeth of patients with pyorrhea were inoculated into the inner margin of the gum of the lower posterior teeth in 25 guinea pigs. Each of 5 pigs received 0.25 cc. of pyorrhea material. Four animals remained normal, the fifth, after 5 days, developed an enlarged gland deep in the neck immediately below the mandible. The gland gradually enlarged during the following week and the infection spread to the surrounding cellular tissue.

Studies on the respiratory exchange and the sugar, non-protein nitrogen, chlorides and carbon dioxide content of blood, were made on anesthetized (morphine + amytal) dogs. Tracheotomy was done and connection made to a Benedict universal apparatus. Blood analyses were done by standard methods. The high frequency current had the following characteristics: wave length—200 meters, relatively high voltage, currents from 500 to 1000 milliamperes. Electrodes were placed on the left upper arm and right thigh, or on either side of the head. Treatment continued from 1 to 3 hours. Temperature measurements were made with thermocouples and mercury thermometers.

The respiratory metabolism invariably increased—in some cases 150%. Body temperatures were elevated 5 to 7°C. When blood sugar was initially relatively high there was a gradual depletion during diathermy; in cases of low initial concentrations a preliminary rise was noted followed by a fall. The end result was a marked hypoglycemia (30 to 50 mg. per 100 cc. blood). Non-protein nitrogen was in some cases increased to 200% of normal. Chlorides failed to exhibit any gross changes. The carbon dioxide content of whole blood and of plasma invariably dropped to a rather low level (about 35 vol. %). Panting was induced in some animals, during which time the respiratory rate exceeded 250 per minute.

As a preliminary report on the lipid metabolism of tumors, of which little is known, lipids of the transplanted carcinoma of the mouse as well as malignant and benign human tumors were analyzed. The total lipids and phospholipids were determined by Bloor's oxidative method, cholesterol and other unsaponifiable substance by the oxidative method with some modifications. Neutral fat was calculated by the subtraction of phospholipid and cholesterolester fatty acid from total fatty acid. The micro-oxidative determination of cholesterol of Okey was modified in that the cholesterol digitonide after saponification and washing on the glass filter was dissolved by hot absolute alcohol, the solution filtered then evaporated to dryness to get rid of alcohol and the residue oxidized. The total unsaponifiable substance was obtained as follows: The lipid solution was saponified with sodium alcoholate, then acidified and extracted with petroleum ether. The petroleum ether was then added to equal volumes of absolute alcoholic sodium alcoholate and water whereby the fatty acids are separated as soap in the alcohol-water while the unsaponifiable remains in the petroleum ether. The unsaponifiable substance in the petroleum ether is recovered by evaporation, determined by oxidation and calculated as cholesterol.

The average value of lipid analysis in tumors is tabulated: (Lipid content is expressed as gm. per 100 gm. dry tissue.)

The high lipid content of malignant tumors is notable. The high phospholipid content in malignant tumors as compared with benign tumors seems to be of particular interest. The water content of tumors is generally high as has been reported, little difference was found in the content of residual or unknown unsaponifiable substance. The experiments are being continued.

Recent studies of peripheral vascular diseases have brought out the importance of differentiating the element of spasm from that of organic occlusion. Vasoconstriction can be demonstrated in the extremities of most individuals with normal blood vessels by measuring the surface temperatures. This action is present in varying amounts depending on the interplay of environmental conditions and the nervous mechanism. It possesses a definite gradient 1 so that it usually begins about the knee and progressively increases distally. Consequently the toes are normally the coldest parts of the lower extremity. These surface temperature differences can under certain conditions be made to disappear. In a series of 22 individuals with normal vessels it was found that this took place when the lumbar sympathetic fibres were paralyzed by spinal anesthesia. All surface temperatures of the extremities came to approximately the same level, with a variation of ±1.7°C. from the mean. This evidently represents a condition of physiological vasodilatation in the vessels of the extremities and we have called it “the normal vasodilatation level.” Its importance consists in that it permits an accurate estimate of the degree of spasm in any given case of vascular disease. The failure to react to the normal level in the latter signifies the presence of organic occlusion, the degree of which is measured by subtracting the maximum temperature achieved from the normal vasodilatation level. Having established the response to known regional sympathetic paralysis, we now report the effect of certain general anesthetics upon the vasoconstrictor gradient in order to simplify if possible the methods for gaining this information.

We have found that nitrous oxide-oxygen, ether, and tribromethyl alcohol individually in anesthetic doses will completely obliterate the vasoconstrictor gradient.

It has been noted by many early observers, among them Wright, 1 that the coagulation time of blood was decreased after meals. Schreiber 2 and Kehr 3 suggested the preoperative and postoperative use of intravenous glucose in obstructive jaundice, but it was not used extensively until Crile and Walters advocated it 5 years later. Partos and Svec 4 pointed out that a relation existed between the sugar content and coagulability of the blood, namely, that with increasing blood sugar the clotting time is reduced. They demonstrated this effect following the injection of various substances which produce a hyperglycemia, e. g., glucose, epinephrine, theobromine sodium salicylate and morphine. Ravdin 5 presented a series of experiments in which he attempted to justify the use of intravenous glucose in cases having lesions of the biliary apparatus and who were poor operative risks.

In determining coagulation time we used 2 methods simultaneously in all cases, (1) that of Lee and White 6 and (2) a modification of the method of Wright 7 (using pieces of glass tubing 40 mm. long and 2 mm. internal diameter). Tests for coagulation were made every half minute. The two methods usually checked within one-half minute; often the results were identical; occasionally a minute's difference was observed, especially in cases where the coagulation time was very long, as in the jaundiced animal. Serum calcium determinations were made by the method of Kramer and Tisdall. 8 , 9 Blood sugars were determined, using the Folin-Wu technique. 10 Serum bilirubin was determined by Thannhauser and Anderson's modification of van den Bergh's method. All experiments were done on dogs fasted over night.

Both normal and jaundiced dogs were used.

Recently Wangensteen and Lynch 1 indicated that the accumulation of gas in the small intestine as visualized by X-ray examination was an early and reliable criterion of obstruction to the continuity of the bowel. In this study an attempt has been made to evaluate the significance of X-ray evidence in the early recognition of strangulation obstruction.

Strangulation obstruction in dogs was established under aseptic conditions employing local anesthesia (procaine) of the abdominal wall fortified by the preliminary injection of morphine sulphate.

In each instance about 24 inches of small intestine together with its mesentery was tied off about 18 inches above the ileocaecal valve. Umbilical cord tape was used for the tie and an attempt was made to establish varying grades of strangulation which might be designated on the basis of I-IV, IV being the maximal grade of strangulation obtained. In the grade IV strangulations, the blood supply to the loop was arrested; in grade III there was immediate congestion and discoloration of the bowel but slight pulsation could still be felt in the mesenteric loop beyond the ligature after placement of the tie. It was found to be extremely difficult to establish strangulation obstructions of grades I and II, and these experiments concern strangulation obstructions of grades III and IV. In 2 dogs mild (Grade I and II) strangulation obstructions were established; these survived the procedure and subsequent laparotomy showed the continuity of the bowel uninterrupted despite the angulation of the loop. Twelve animals in which grade III and IV strangulations were established serve as the basis for this report. Perforated lead shot were sewed to the mesenteric border of the strangulated loop in an effort to determine whether the bowel proximal to the obstruction or the strangulated loop distended most readily.

In recent years evidence has accumulated that seriously questions the almost universally accepted belief that the absorption of a toxin from the intestinal canal is responsible for the death of the animal with simple obstruction of the bowel. There exist, however, a few bits of evidence which would substantiate such a belief. Sugito 1 found that blood serum obtained from obstructed dogs when injected into the peritoneal cavity of rats provoked toxic symptoms. Scholefield 2 has obtained results of a similar nature, but it is a noteworthy fact that he found no evidence of a toxic substance in the portal blood until the dogs were in a moribund condition.

In this study, 6 dogs were obstructed by severing and inverting the ends of the bowel in the lower ileum under aseptic conditions. When it was apparent that the obstructed animal was rapidly failing, the abdomen was opened under ether anesthesia and a large mesenteric vein was divided and the portal blood collected into a 3% solution of sodium citrate, (10 cc. per 100 cc. of blood). The blood thus obtained was injected into the external jugular vein of a normal anesthetized dog under aseptic conditions and the blood pressure of the recipient was registered by means of a cannula introduced into the carotid artery. Two other experiments were employed as controls. In one of these, 220 cc. of blood was obtained from the carotid artery of a normal dog and collected in the citrate solution. To this citrated blood 10 mg. of histamine dichloride was added. In the other control experiment, 100 cc. of 1% sodium citrate solution was administered intravenously without the addition of the blood.

The transfusion of the blood from the normal donor to which histamine was added resulted in an immediate and protracted drop of blood pressure to about one-half of the original reading despite the increase in blood volume; 17 minutes later the blood pressure almost regained the initial normal level.

The cells which are grouped together under the name of the reticulo-endothelial system phagocytose particulate material and destroy or neutralize the action of many soluble toxins present in the circulating blood. The present study was made to observe if a partial blockage of the phagocytic ability of the reticulo-endothelial system had any effect on the length of time an animal would survive following the production of a complete obstruction in the distal portion of the ileum.

Rabbits were selected as most suitable for these experiments. All surgical work was performed under ether anesthesia and with sterile technic. Routine necropsy examinations were made on each animal. To determine the length of time a normal rabbit would live following the production of a complete obstruction in the distal portion of the ileum the following preliminary experiment was performed: In a series of normal rabbits which weighed between 1200 and 3100 gm. a complete obstruction was made by placing a tie of tape 10 cm. proximal to the ileo-cecal valve. Three rabbits lived from 40 to 50 hours; 3 lived from 60 to 70 hours, and 4 lived from 70 to 89 hours after the operative procedure. Forty-four hours was the shortest period while 89 hours was the longest period any animal survived the operation. The average length of life was 65.8 hours. A second series of 11 normal animals which weighed between 1150 and 3000 gm. were selected. A colloidal preparation of graphite was made and injected intravenously at daily intervals. To avoid the formation of emboli the first injection consisted of as small quantities as 0.5 cc. of the graphite preparation. This amount was gradually increased until 10 cc. was injected at one time.

The adrenal glands perform a number of functions which appear necessary for normal mammalian life. Some animals, especially rats and rabbits, are, however, able to survive bilateral adrenalectomy for several weeks. Many interesting experiments have been performed to show that the adrenal glands secrete a substance or substances which act as a special defensive agent in the destruction of various types of toxins. The detoxifying substances are believed to be elaborated principally by cells of a reticulo-endothelial nature which are located in the cortex of the gland.

The cause of death in low intestinal obstruction is not well known. Cutting 1 has, in a recent article, presented experimental evidence which seems to show that a material elaborated in the adrenal cortex neutralized or destroyed a toxin or toxins responsible for the effects of intestinal obstruction. The adrenal glands were, therefore, considered to act as a specific mechanism against a toxemia present in all cases of advanced intestinal obstruction. These deductions stimulated us to perform a group of experiments for the observation of the effects produced by the intravenous injection of a toxic material into animals on whom various types of operations had been performed. All surgical procedures were done with sterile technic and ether anesthesia. Bilateral adrenalectomies, unilateral adrenalectomies, cholecystectomies, unilateral nephrectomies, splenectomies and appendectomies were done on a group of 32 rabbits. Ten of the animals survived the operative procedure and appeared well 3 weeks later.

Complete intestinal obstruction was produced in a group of 10 rabbits by placing a double tie of linen tape 10 cm. proximal to the ileo-cecal valve.

Clairmont and Haberer 1 first directed attention to the terminal anuria that occasionally accompanies protracted obstruction of the common bile duct. This happening has frequently been observed since then but the mechanism of its occurrence is not well understood. It has been believed that the administration of ether anesthesia to patients with obstruction of the common bile duct has played a significant rôle in precipitating this event.

In this study we had planned to determine whether any of the commonly employed anesthetics have a deleterious influence on the kidney function in the presence of obstructive jaundice. Not having obtained any manifestations of such injury with chloroform or ether no further observations were made with other anesthetics in common use.

The common bile duct was divided and ligated in 16 normal dogs under aseptic conditions. Following the convalescence of the animal, deep ether anesthesia was administered for an hour at brief intervals (usually a week apart) following which the excretion of phenol-sulphon-phthalein and the blood urea and icterus index were obtained on 2 occasions soon after recovery from the anesthetic and again before its repetition a week later. In a few other dogs similarly obstructed, chloroform was administered in one instance by stomach tube and to 4 others by inhalation.

Blocks of tissue from the kidney and liver were obtained at necropsy from all the dogs that served as subjects of these experiments. The kidneys exhibited typical tubular degeneration; in most instances this finding was striking. Fat stains made of the kidney showed a corresponding fatty degeneration of the tubules. Biliary pigment and albumin were usually observed within the lumen of the tubules. Bile pigment was also found deposited within the renal cells.

The rôle of the phagocytes in the mechanism of resistance to infection has been recognized since the early work of Metchnikoff in this field. Little work, however, has been published on the fate of the toxins of the ingested bacteria. The present study was undertaken with the view of determining the rôle of fatty acid compounds of the phagocytes in neutralizing diphtheritic toxin.

Pus from various types of abscesses was studied, particularly with reference to its ability to neutralize diphtheritic toxin. One gram of pus, it was found, would neutralize from one to 4 M.L.D's of toxin, depending upon the nature of the material and the time of contact. The pus was then dessicated and extracted with alcohol and ether in order to remove the fatty acid compounds. The residue, it was found, possessed no neutralizing properties whatever. The extracted fatty acids which were chiefly of the oleic series, when saponified, neutralized diphtheritic toxin in ratios comparable to those published in earlier work from this laboratory. 1

It is not only the salts of the unsaturated fatty acid series which neutralize toxins. Some of the esters, such as lecithin, cholesterin, and kefalin also possess active detoxifying properties. It seems probable, therefore, that the fatty acid compounds of the body play an important rôle in the mechanism of resistance to bacterial toxins.

The experiments and observations of Swift 1 and Birkhaug 2 showed that there is marked similarity in the hypersensitiveness (allergy) to streptococci in animals made hypersensitive experimentally and in patients having acute rheumatic fever.

With this similarity in mind we have carried on a series of experiments in animals to determine the relation between hypersensitiveness and the concentration of antibodies in the blood.

Rabbits were made hypersensitive to streptococci according to Swift's method by injecting 5 cc. of agar heavily seeded with streptococci into the subcutaneous tissue in one area. In from 12 to 15 days these rabbits were injected subcutaneously with 1/100 of a standard amount of streptococci in each of 10 places on the right side and with 1/1000 of the amount in each of 10 places on the left side. The character, number, and size of these nodules were used as an indicator of the degree of hypersensitiveness of the animals. Some of these hypersensitive animals were injected intravenously with streptococci from 3 to 5 days before the multiple subcutaneous injections were made. The serum of the animals was tested for agglutinins at the time of the multiple subcutaneous injections and 5 days later when the animals were killed and the nodules examined.

The following facts were observed: 1. In the hypersensitive animals gross lesions, often large abscesses, were frequently seen. 2. The humoral immunity as indicated by agglutinins was relatively low. 3. Giving an intravenous injection of streptococci to these hypersensitive animals, in from 3 to 5 days before the multiple subcutaneous injections in the back, prevented the development of subcutaneous nodules. 4. These desensitized animals showed a high humoral immunity as indicated by a high agglutinating titer.

Gall bladder disease is a factor common to the majority of cases of acute pancreatic necrosis. The mechanism by which gall bladder disease predisposes to pancreatic necrosis has not been established. In this study we have tried to evaluate the factor of reflux through the agency of mechanical obstruction at the ampulla in the cat. The terminal portion of the common bile duct embedded in the wall of the duodenum was exposed and a ligature placed creating a common channel of the bile and pancreatic ducts.

The criterion of pancreatic necrosis used in this work was the actual histological demonstration of necrosis in the pancreas. Postmortem autolysis and fat necrosis were differentiated from true pancreatic necrosis by the absence of microscopic cellular reaction in these areas.

In a group of 7 cats, 1 developed pancreatic necrosis following simple establishment of ampullary obstruction. In another group air was injected into the gall bladder at the time the obstruction was established until the gall bladder became so distended that its contents were spontaneously evacuated. Through the agency of the block at the ampulla regurgitation occurred into the pancreatic duct. In a group of 13 cats, 8 developed pancreatic necrosis. The pressure in the common bile duct occasioned by the emptying of the gall bladder was measured in 5 cats and was found to vary between 190 mm. and 240 mm. water.

In another group ampullary obstruction was established and gastrostomy was also done, after which the cats were given frequent feedings of olive oil, cream, and bile salts through the gastrostomy tube. Of 31 cats pancreatic necrosis was observed in 15.

To another group alcohol was fed through the gastrostomy tube. Of 9 cats, 2 developed pancreatic necrosis.

I. No tissue investigated caused any striking accelerating of healing. 2. The healing time of the control wounds was predicted by calculation with an average error of 18% for the whole series.

Partition of serum calcium in 16 cases of vascular hypertension without treatment showed the average value for diffusible calcium to be 57% of the total serum calcium. Determinations carried out on 5 apparently normal individuals of similar ages gave an average value of 65% for diffusible calcium. The average total serum calcium for both groups was almost identical, being 10.3 mg./100 cc. for normals, and 10.5 mg./100 cc. for hypertension cases.

In hypervitaminosis D, produced in adult rabbits by feeding large doses (26,000 to 61,000 rat units per day) of irradiated ergosterol dissolved in sesame oil, 1 the percentage of diffusible calcium decreased from an average normal value of 58% to 49% of the total serum calcium. The average total serum calcium in these animals increased from 14 mg. to 17 mg. per 100 cc. of serum. Inorganic phosphorus values in this condition increase to approximately twice the normal value. Serum proteins remained unchanged in hypervitaminosis D, the average normal value being 6%.

Daily doses equal to or greater than 26,000 rat units of irradiated ergosterol were found to be definitely toxic for adult rabbits weighing from 2 to 3 kg., if administered for 15 days or longer.

The apparatus used in these experiments has been previously described in a paper published in this journal, 1 and consists of a Cooper-Hewitt quartz mercury-vapor arc as the source of radiation, running at 100 volts D. C. A quartz rod placed at right angles to the axis of the arc, and pointed and bent at a slight angle served to conduct the radiation from the arc to the desired point on the heart's surface. As previously reported for Fundulus hearts, it was possible to obtain an increase in rate of heart beat, or a decrease in rate depending on the length of the period of exposure.

Short exposures in the region of the sino-auricular node of both frog and turtle produced a noticeable increase in rate. When the exposure is too long continued, a decrease in rate follows, and the normal sequence of auricle and ventricle beats may be interfered with. In this connection, further experiments are being done and will be reported in a later paper. Experiments with ultraviolet radiation and heart-block are also under way.

It has been possible to stimulate the heart of a frog to regular beat, normal in sequence and in amplitude, by radiation at the sinoauricular node after the heart has been quiescent for an hour or more. Whether this be a question of stimulation of the pace-making region to greater activity so that the magnitude of the impulse is great enough for conduction through the heart tissue, or whether the pacemaking region is entirely quiescent and is at once stimulated to activity by the exposure, remains to be determined.

Since the work of Cullen 1 and others on the determination of the pH of serum with quinhydrone, some investigators have had difficulty with this method, because of the rapid drifts in potentials. Cullen, Wilson 2 and others have reported that satisfactory quinhydrone serum pH determinations can be made by reading potentials rapidly at noted times and extrapolating in order to obtain the potential at zero time.

In a recent study at this laboratory it was necessary to perform a large number of dog serum pH determinations, and it seemed desirable to check the colorimetric method by an electrometric method. When parallel pH determinations on dog serum were made with the colorimetric method, using the Hastings bicolorimeter 3 and with quinhydrone at room temperature (24° to 26°) it was found that the 2 methods agree to within 0.02 pH. The quinhydrone method is very rapid and convenient, and since it is free from the personal factor of matching colors, it has, in our hands, been more reliable than the colorimetric method. The procedure is briefly as follows:

The electrode vessel consists of 2 ordinary glass tubes which fit snugly one inside the other, a rubber connection which holds the tubes in any desired relative position, and a platinum wire sealed into the inner tube. The inner tube contains mercury through which metallic contact to the platinum wire can readily be made. The outside tube is 8 cm. in length, and 4 mm. in inside diameter, so that its total capacity is about 1 cc., although these dimensions can be varied at will. By moving the inner tube up or down through the outer tube, liquid can be conveniently drawn up or expelled.

Until the work of Cecil and Blake 1 lobar pneumonia had not been produced constantly and successfully in the lower animals. These authors employed the Macacus syrichtus, a Philippine monkey which is apparently more susceptible to the pneumococcus than the other varieties. Their method consisted simply of intratracheal injections of small quantities of pneumococci. The disease produced and the lesions observed corresponded closely with lobar pneumonia in man. However, the subsequent employment of this method with other species has failed to produce lobar pneumonia apparently because they were more resistant to the pneumococcus than the Macacus syrichtus which unfortunately is no longer allowed to be imported into the United States. Others working with the dog have found that in order to produce pulmonary infection with the pneumococcus, not only must the infecting agent be implanted far down in the bronchial tree but the inoculum must be massive. Lamar and Meltzer 2 using this method were successful in producing in some of their animals lobar consolidation and a disease resembling an abortive lobar pneumonia. But the infected animals which lived longer, died within 2 to 4 days with bacteremia and pyemic complications without true consolidation of the lung. Many of their dogs escaped infection. More recently Coryllos and Birnbaum 3 have employed a modification of this method, spraying large quantities of pneumococci culture into the lung through a bronchoscope either with or without subsequent occlusion of the main bronchus. This resulted either in a transient infection or a widespread pneumonia accompanied by atelectasis with an ensuing generalized infection and fatal termination.

Thus the methods previously used in an attempt to produce lobar pneumonia in dogs, not only have failed to induce the characteristics of the disease as seen in humans, but have employed a dosage which is enormously greater than could occur in the spontaneous inception of the disease in man.

Much of the literature on microbic dissociation has emphasized the occurrence of rough (R) colonies, in contrast to the smooth (S) form, with, on the whole, relatively little mention of other colony types. In contrast to this, it has been the writer's experience that frequently many variant colonies of different character are encountered.

The results presented in the accompanying table were obtained in connection with a study of factors which might stimulate the process of dissociation. They are typical of many other similar experiments and illustrate the changes in colony form which were found in cultures of certain of the colon-paratyphoid-dysentery organisms. Smooth forms, previously carried through a series of colony isolations, were used for inoculation of the broth or peptone media. The appearance of variant colonies was followed by streaking agar plates of standard composition at intervals. The changes thus represent those occurring in “ageing” cultures.

The change from S to R appeared to be a gradual one and was not accomplished by distinct or abrupt changes from one colony type to another. All gradations in colony form from the typical white homogeneous colonies with even margins, characteristic of the S form, to the flat, dull, dry-looking, coarsely-granular and irregular colonies of the R form were found. Colonies appearing to fall between these two extremes are referred to as intermediate (I) forms in the table. It will be seen that in ageing cultures such colonies were usually present in large numbers and often far out-numbered the true R forms. At times the change went no farther than the intermediate stage and true rough colonies were never seen, though there was nevertheless a decided departure from the typical smooth form.

In our study of the factors influencing change in colony form it was found that repeated transfers in dextrose broth were quite effective in causing reversion of R to S forms of Bact. dysenteriae, Sonne. A typical experiment is shown in the accompanying table.

In this and in similar experiments with different R isolations of other strains, irregularity in the rate of reversion to the S form was always seen. In some cases S colonies appeared early in the series of dextrose broth transfers and soon entirely replaced the R forms, while in other instances only a few S forms resulted even after a number of transplants. Also, intermediate and other variant colony forms were more rarely encountered here than in the course of the S to R change.

In a number of instances cultures which had undergone the S to R change in broth or peptone solutions and then the R to S reversion in dextrose broth were subjected to comparison with the original or parent S culture of the same strain. The newly converted S forms produced the same uniform turbidity in nutrient broth and similar fermentation results in dextrose, lactose and sucrose broths, and they were agglutinated by immune S serum apparently in as high dilution as was the parent S culture. In 0.85% salt solution, however, the recently derived S forms showed some tendency to spontaneous agglutination, while the original S culture showed no such tendency.

In normal animals the chloride content of the blood is maintained at 280-320 mg. percent, even under the conditions of a negative chloride balance. Distilled water, injected intraperitoneally in rabbits rapidly acquires a chloride concentration up to 376 mg. percent and becomes isosmotic 1 Consequently, by the transperitoneal perfusion of distilled water, it is possible to produce an experimental hypochloremia by dialysis. 2 The blood chloride falls and a large amount of chloride, as well as other electrolytes and organic crystalloids, is found in the dialysate. Rabbits thus treated develop muscular fibrillation, tremors and convulsions and die in from 2 to 5 hours. In a series of 13 rabbits so dialyzed, we found an average of 619 mgs., (from 205 to 896 mgs.), of chloride was removed from the animal as determined by analyses of the perfusate. During the corresponding period of dialysis, the average fall in blood chloride was 79 mgs. percent, (from 300 to 221 mgs.). As the blood volume in the rabbits used was empirically about 200 cc., not more than 175 mgs. of the dialyzed chloride could be accounted for as coming from the blood itself. The source of the other 440 odd mgs. of chloride was evidently other body tissues. As a result our attention has been turned to the chloride content of the tissues.

Two of us (C. B. D. and M. E. H.) have recently determined the chlorides in various tissues from the rabbit. As our primary interest at the time lay in the various lipoidal fractions, these analyses were all made upon dried tissues. The animals were killed by bleeding. The desired tissues were quickly removed, cut to shreds and dried in a current of warm air (40°C) for 10 hours.

The total blood volume, red cell count, volume ratio of corpuscles to plasma, reticulocyte count, hemoglobin and size of the red cells of rabbit from 6 hours after birth to 8 months of age have been studied. At birth the R.B.C. are 4 to 5 million per cu. mm.; the Hb is 13 to 16 gm., the volume ratio of corpuscles to plasma and the total blood volume are higher than at maturity. The size of the R.B.C. is 1/3 to 1/2 times larger than the adult R.B.C. The reticulocytes are 25% to 30% of the R.B.C. at birth and 1% to 3% at maturity

Rabbits with thyroids removed approximately 3 weeks after birth develop an anemia which simulates clinical pernicious anemia in that the hemoglobin per cell count is relatively higher than in the normal adult. The R.B.C. are also larger than the normal adult R.B.C. Metamyelocytes and poikilocytoses are present. Feeding liver extract (Lilly) to these rabbits increases the R.B.C. and brings the hemoglobin cell ratio back to normal.

In some recent investigative work, 1 two factors were found essential in the experimental production of massive atelectasis of the lung in dogs, viz., A straining type of respiration, and secondly, some form of obstruction to the bronchus of the lung lobe; either total or valvular. In this work an artificial means of obstruction was used, this obstruction being located in the primary bronchus of the lung lobe.

Either total or valvular obstruction, in the presence of a staining type of respiration, was followed by a massive atelectatic condition of the obstructed lung. If a quiet, normal type of respiration was exhibited, no resultant atelectasis was observed. An example was given of complete obstruction of a secondary bronchus, of 6 weeks'duration, with quiet respiration in which no atelectasis occurred.

In carrying out some experiments with thermal and silver nitrate cautery, 2 , 3 it was found that cauterization of a bronchus was followed by complete stenosis in from one to 2 weeks. If this stenosis was located in the primary bronchus of the lung lobe, that lobe was found to be completely atelectatic with the secondary bronchi and bronchioles filled with a mucogelatinous material. However, if the stenosis was located in one of the several divisions of the primary bronchus to the lobe, no resultant atelectasis occurred; only a filling of the secondary and tertiary bronchi and bronchioles distal to the stenosis with the mucogelatinous material.

Group A. 4 dogs. Silver nitrate or thermal cauterization of a secondary bronchus of a lung lobe. Sacrificed at the end of 2 to 6 weeks. Results: Total stenosis of secondary bronchus with no atelectasis distal to the stenosis.

Group B. 7 dogs. Silver nitrate or thermal cauterization of the primary bronchus of a lung lobe.

The experimental chronic gastric ulcers in rabbits, to be described, were obtained by making acute lesions in the stomach, which subsequently became chronic. An operative procedure was used which consisted in the excision of a piece of the gastric mucosa by means of a certain technic which has been described. 1 A series of chronic ulcers was collected ranging in age from 3 months to a little over 2 years. Large Flemish Giant rabbits were used. These animals usually live to be about 5 years old and an ulcer of 2 years'duration, therefore, occupies a large part of the life cycle of the rabbit. All animals were kept under the same conditions, and fed identical diets composed of hay, oats, carrots and some lettuce. The ulcers were fixed in formol-Zenker solution, serial sections were made, and stained with ordinary and differential stains.

From a histologic standpoint there are 2 main structures in chronic ulcers to be considered, i. e., the margin and the base. The margin is formed by mucosa which is composed of glands that decrease in length and are separated by relatively more connective tissue as the edge is approached. The last glands tend to overhang the ulcer and fall over into the crater. The cells composing these glands are all of one type, the foveolar cells. These are the cells that line the foveolae of normal gastric glands and have been shown to be the ones responsible for the regeneration of epithelium in acute gastric ulcers. (Ferguson. 1 ) In chronic ulcers a few of these cells invariably extend from the last marginal glands outward onto the floor of the ulcer. This indicates that the epithelium at the margin, in even the most chronic ulcers, is continually trying to grow out and cover the defect.

The influence of various concentrations of bile upon the gastric secretion in dogs with non-leaking fistulous openings in the stomach has been reported. 1 Some phases of the problem of antigenic absorption through an intact body surface covering layer have been reported, 2 and further work is in progress. This report deals with use of egg white as a vehicle to introduce an antigenic substance into the lumen of the small intestine. Bile has been used by Besredka 3 to sensitize or prepare the intestinal mucosa for antigenic absorption in his oral vaccination against the enteric group of infectious diseases. Arnold 4 offered a different explanation for the action of bile than that suggested by Besredka. Bateman 5 received the literature upon the digestibility and utilization of egg white in dogs and man. Raw egg white leaves the stomach more rapidly than other foods. Bateman showed that diarrhea followed the ingestion of certain amount of raw egg white. Arnold 4 showed that raw egg white injected into the duodenum of dogs caused increased permeability of the wall for bacteria.

Four dogs with non-leaking gastric fisulae were used for these experiments. The material placed into the gastric lumen through the fistulous opening was raw egg white (25 cc.). raw egg white (25 cc.) suspended in 200 cc. of distilled water and a mixture of raw egg white (25 cc.) desiccated ox bile (Difco 1 gm) suspended in 100 cc. of distilled water. The accompanying graph gives the average gastric acid secreting response to these substances. Stomach contents (1 or 2 cc.) were removed at half hour intervals and titrated in the usual manner.

The experimental work of Mason 1 called our attention to the extremely toxic reaction produced by the implantation of liver into the abdominal cavity of animals. Ellis and Dragstedt 2 showed that death of these animals was not strictly due to toxemia but there was a constant finding of large numbers of organisms of the B. welchii group in the abdominal cavity and drew attention to the fact that this B. welchii organism was a normal inhabitant of the livers of dogs. They implanted fetal liver into the abdomens of dogs and also adult livers which had been previously autoclaved and found that no toxic reaction ensued. Our experiments were undertaken with a view to establishing the mechanism of death in peritonitis due to liver autolysis. It was found earlier in the course of these experiments that if the liver was ground and allowed to autolyse and then sterilized that its implantation into the abdomen caused the same picture of an overwhelming B. welchii peritonitis as when the infected liver had been used. The seeming contradiction in the work of Ellis and Dragstedt is probably due to the fact that in their experiments the hard cooked mass of liver had less exposed surface and did not undergo autolysis so promptly. There is, therefore, some mechanism at work by which the ordinary flora of the intestine as represented by the Welch bacilli are allowed to make their way through the intestinal wall and infect these masses of autolysed liver which are shown to have been previously sterile by culture.

The following attempts were made to isolate the toxic factor in this reaction. 100 gm. specimens of liver were ground and incubated for 24 hours and then extracted with large amounts of water.

Griffith 1 was the first to show that type-specific, S, pneumococci may be transformed from one specific S type into other specific S types through the intermediate stage of the R form. He showed that the transformation of R forms, derived from one specific S type, into S forms of heterologous types may be effected in vivo by the following procedure: The subcutaneous injection, in white mice, of small amounts of living R forms together with suspensions of heterologous S cultures, killed by heating. Griffith further reported that all attempts to secure transformation of type by in vitro methods were unsuccessful.

Griffith's observations were confirmed and extended in recent publications by one of the authors. 2 In these communications it was also reported that all in vitro attempts to effect transformation of type were unsuccessful.

Recently we have renewed the in vitro studies and have succeeded in evolving a relatively simple technique for inducing transformation of pneumococcal types in the test tube.

For the purposes of convenience we have confined our present studies to the transformation of a 2R culture into Type III S organisms. However, since it has been shown in previous work that an R culture may be transformed in vivo into S organisms of any heterologous type it is probable that similar transformations may also be effected in vitro.

The procedure consists in seeding minimal amounts of an R culture into a suspension of S organisms of heterologous type, killed by heating. Certain conditions, while not absolutely necessary, apparently facilitate the transformation process. Some of these conditions are : (1) The amount of the R inoculum introduced, (2) the incubation of the cultures for a longer time than the conventional period, (3) the addition of a small amount (10%) of anti-R serum, (4) the addition of a small amount of blood-broth.

Two successive extractions of the sap were made from the vacuole of each living cell of Nitella flexilis. The first extraction, called for convenience “sap”, was made without pressing on the cell wall, while the second extraction, called “sap mixture”, was made by squeezing the cell wall vigorously. The pH value of the sap was found to be 0.6 pH lower than that of the sap mixture. This difference may be entirely due to the presence of the protoplasm in the latter, or partly due to the presence of fluid from the space between the cell wall and the protoplasm.

The pH values of the sap and the sap mixture remained unchanged during the period of extraction and of the subsequent measurement by the glass electrode.

The sap. (1) 0.07% cresyl blue, azure B, and methylene blue salt do not alter the pH value when dissolved in the sap in vitro, but 0.07% free base of cresyl blue and azure B cause it to increase about 0.5 pH with the former and 1 pH with the latter.

(2) a. When 0.07% dye has penetrated from the solution at pH 9.2 there is an increase in the pH value of the sap of 0.5 pH with cresyl blue, and 1 pH with the azure B or with the dye penetrating from methylene blue solution.

b. Spectrophotometric measurements show that cresyl blue and azure B penetrate as such while it is chiefly azure B that penetrates from methylene blue solution which always contains azure B as impurity.

(3) a. 0.07% cresyl blue penetrating in 15 minutes from the dye solution made up in buffer at pH 9.2 or at pH 6.8, or in tap water, raises the pH value of the sap equally (0.5 pH).

(1) The pH value of the sap extracted from the vacuoles of small living cells of Valonia macrophysa is found to be pH 5.4. The pH value remains unaltered for several hours, i. e., much longer than the period required for the extraction of sap and subsequent measurement with the glass electrode.

(2) 0.01% cresyl blue penetrating (in about 20 minutes) from the sea water at pH 9.5, raises the pH value of the sap 0.5 pH. This increase is 0.2 pH less than the rise brought about by the addition of 0.01% free base of cresyl blue to sap in vitro.

(3) 0.03% cresyl blue penetrating (in about 1 hour) raises the pH value about 0.9 pH, which is about 0.4 pH less than the rise brought about by the addition of 0.03% cresyl blue free base to sap in vitro.

(4) If cells are kept 8 hours longer in this cresyl blue solution, they appear to be still in good condition, so that it is likely that the cells described under (2) and (3) are not at all injured.

(5) No alteration in the pH value of the sap occurs when cells are placed even for 8 hours in sea water at pH 9.5 containing no dye.

(6) Azure B penetrating the sap also increases the pH value, and this increase is again less than the increase brought about by addition of azure B free base in vitro. Owing to a slower penetration and greater toxicity of azure B as compared to cresyl blue, these results on azure B are rather unsatisfactory but experiments are being continued.

(7) The penetration of dye from methylene blue solution at pH 9.5 is still slower than from the azure B solution, so that sufficiently accurate results are not obtainable before the cells are injured but experiments are being continued.

For the purpose of rapid determination of ether concentration in ether-air mixtures we have found the thermal conductivity method of gas analysis satisfactory. Since the heat conductivity of ether vapor is only about one half as great as is that of air, the admixture of ether vapor with air decreases the loss of heat from the wire and causes its temperature to rise. The consequent increase of electrical resistance of the wire is readily determined and, if the apparatus is calibrated, the change of resistance is a measure of the ether concentration.

The apparatus used in this investigation consisted of a rectangular brass block 14×4×2 cm. in size through which 2 parallel holes 1 cm. in diameter were bored longitudinally. In each cell a platinum wire 0.005 cm. in diameter was suspended axially from plugs closing the ends, and heated by a current of 0.2 ampere. The gas was introduced through lateral tubes close to the ends of the cells. The calibration was effected by means of several ether-air mixtures of known concentration. These were made up by breaking, in a closed flask of known volume, a capillary tube containing a weighed quantity of ether. The mean experimental error of the determination was about 5% with concentrations between 0.3% and 1.3%. It is probably considerably less than this with mixtures of the usual anesthetic strength (6%-8%).

For concentrations of less than about 5% the resistance of the wire was approximately proportional to the concentration. When, however, larger concentrations were used proportionality no longer obtained. With concentrations greater than 10% the apparent heat conductivity began to increase until with mixtures of about 30% it was equal to that of the air Mixtures stronger than 30% had a cooling effect greater than that of air.

Our investigations on the protective effect of granulation tissue (Gay and Morrison 1 ) (Gay, Clark and Linton 2 ) against a highly virulent streptococcus introduced into the pleural cavity of rabbits, led us to attribute a predominating if not exclusive rôle to mononuclears as compared with polymorphonuclear cells. In the acute stage of the inflammatory process when polymorphonuclears predominate the animals are fully as susceptible as normal controls. We have never denied that polymorphonuclears have a distinct protective energy with some bacteria and in some locations.

Opie 3 in a recent article has reported similar experiments in the peritoneum and shown that early stages of inflammation (polymorphonuclear) prevent temporarily the invasion of the blood stream by the streptococcus, but further shows in complete confirmation of our results that recovery from such infection depends on the establishment of a later stage of inflammatory exudation. He does, however, suggest that our conclusions as to the negative or actually injurious effect of an excess of polymorphonuclear cells are open to another interpretation. It might be, to paraphrase and extend his remarks, that the sterile irritant (aleuronat) so long as it remains injurious is evidenced by polymorphonuclears and the introduction of a second irritant, the streptococcus, at this period leads to a fatal result. We have often thought of still another objection to our own conclusions, namely, that the pleural exudate in 20 hours is excessive in amount (5-10 cc. on the average) and might actually furnish a favorable location for the streptococcus to multiply. This particularly in view of our later observations that actual destruction of the streptococcus in the protected animals takes place not in the exudate itself but in the granulation tissue of the parietal pleura.

Innumerable “acute” experiments have been reported in the literature on the effect of thyroid administration on the pressor response of laboratory animals to adrenaline. The results have been in the main ambiguous. In contrast to these experiments, in this work an effort was made to insure a hyperthyroid condition of the animal by the long-continued administration of thyroxin.

Large vigorous cats were selected. Some were first fed Squibb's thyroxin tablets daily and then received daily intravenous injections of synthetic thyroxin (Hoffmann-La Roche). Others received the intravenous injections alone from the beginning of the period of thyroxin treatment. The total amount of thyroxin given per cat varied from 40 to 80 mg. The length of period of thyroxin administration varied from 35 to 57 days. At the end of that time blood pressure tracings were made from the carotid artery in the usual manner before and after the intravenous injection of a constant dose of adrenaline chloride (0.3 cc. per kg. of a 1:100,000 solution in saline). Paraldehyde (1.5 cc. per kg.) given by tube on an empty stomach was used as an anesthetic, as suggested by the work of Luckhardt and Koppanyi. 1 Sodium citrate (10% solution) served as an anticoagulant. Since some animals proved resistant to the action of thyroxin, only those were taken for the measurement of the pressor effect of adrenaline that showed a decided loss of body weight, 450 to 1000 gm. (1/3 to 1/7 of the original body weight). Five animals were finally chosen. Thirteen normal cats, treated exactly as those in the thyroxin series except for the administration of thyroxin, served as controls. Averages of the results for both series were as follows:

The data clearly show that the same dose of adrenaline produces in the hyperthyroid cat a rise in blood pressure averaging 106% higher than in the normal control animals.

Of 89 rats fed a rachitic diet including non-irradiated muffets, 5% survived a per Os enteriditis infection, as compared with 30% of 94 rats fed the same diet including irradiated muffets. Therefore we conclude that the use of irradiated whole wheat (muffets) in a rachitogenic diet fed to rats increases their resistance against infection.

Since the first report, in 1928, 1 of the experimental production of edema in dogs by the method of plasmapheresis, further work has been carried out, the results of which are given in this preliminary report.

Edema has been produced in about 40 dogs, often several times in the same dog, whenever the plasma protein level has been maintained at about 3 gm. % or below. Above this level, edema disappeared promptly. There has been essentially no exception among the dogs used.

Several factors have been controlled. Cardiac damage has been ruled out by bleeding a series of dogs from the external jugular veins. Starvation alone, or with the daily administration of 1500 cc. of saline by stomach tube, gives rise to no significant change in the concentration of the plasma proteins nor to visible edema. The alkalinity of the modified Locke's solution used as a suspending medium for the erythrocytes injected into the dog plays no important rôle.

The regeneration of the plasma globulin is much more rapid than that of the plasma albumin and accounts for most of the sharp rise in the total protein when plasmapheresis is discontinued. This is shown best in the long experiments in which the plasma albumin level remains at about 1 or 1 1/2% with relatively slight fluctuations up or down, while the plasma globulin curve shows striking variations depending upon whether or not plasma depletion is being carried out. The total protein curve parallels closely that for globulin. These results confirm the earlier work of Kerr, Hurwitz and Whipple. 2 It is easy to see, therefore, why the albumin/globulin ratio is usually reversed when there has been a long continued loss of plasma protein.

In earlier investigations it was observed that foliar chlorosis developed during periods of intense insolation of grain plants grown on humus soils which had been limed to correct acidity. In order to determine the cause of this injury 2 sets of Marquis wheat were grown, one on strongly acid humus soil low in mineral matter and the other on a fertile but acid loam. The acidity of a portion of the soil in each set was corrected by applications of pulverized calcium carbonate. A white muslin screen was installed over one-half of the plants when 6 weeks old, the remainder being left exposed to full illumination.

After symptoms of chlorosis had developed in fully insolated plants, entire tops were cut from several plants in each set at 4-hour intervals, frozen, comminuted and pressed under uniform pressure. The expressed sap was collected and its hydrion concentration measured potentiometrically by means of the calomel half cells and a quinhydrone electrode.

The data indicate that chlorosis was definitely correlated with sap hydrion changes attributable to differences in soil reaction and light intensity. The acidity of sap expressed at 4-hour intervals disclosed a diurnal periodicity in all plants but most pronounced in the plants on limed soil under full insolation. Reversals in the acidity gradient were not conincident with the hour of maximal light intensity, which suggests that the thermal factor in insolation may not be as important as its light effect.

Light intensity and soil alkalinity exercised considerable influence upon the level of acidity attained. Limed cultures in the shaded and unshaded sets maintained a lower degree of acidity and exhibited a greater initial decrease in sap hydrion concentration than the corresponding untreated plants exposed to full light intensity.

From the results given it is concluded that the relative amounts of uric acid, non-protein nitrogen, creatinine, urea nitrogen, chlorides and sugar in the blood of xerophthalmic animals are not striking enough or constant enough to constitute a decided change. Further, the hemoglobin and red cell count are not sufficiently altered to show specific lesions in vitamin A deficient animals.

It is believed that anemia does not result from lack of vitamin A.

Cholesterol dissolved in chloroform gives with a mixture of sulphuric and selenious acids (125 mg. of sodium selenite in 25 cc. of concentrated sulphuric acid) a purple color in the upper chloroform layer and a red-brown color in the lower acid layer, which displays no green fluorescence. 1 Solid cholesterol, irradiated with the mercury arc lamp for 30 minutes at a distance of 16 inches, when dissolved in chloroform gives with the sulphuric and selenious acid mixture a dark wine-red color in the chloroform layer, and a still darker wine-red color in the acid layer with the absence of green fluorescence. This reaction takes place in the 1.0% and in the 0.5% solution. In the 0.25%, 0.10%, 0.025% and 0.01% solutions the color reaction is negative. The chloroform layer is more or less purple, while the acid layer is brown and free from fluorescence.

Ergosterol, non-irradiated and dissolved in chloroform, gives with sulphuric acid a colorless chloroform layer and a brownish red, cherry red or orange color in the acid layer in direct light and a green fluorescence in transmitted light. 2 With the sulphuric acid-selenious acid mixture the chloroform layer also remains uncolored, while the acid layer gives a brown color in direct light and no green fluorescence in transmitted light.

Solid ergosterol, irradiated with the mercury lamp for 30 minutes at a distance of 16 inches, dissolved in chloroform and treated with sulphuric or sulphuric-selenious acid, gives a greenish blue color in the chloroform layer in the 1.0% and in the 0.5% solution. The acid layer, however, does not differ in color from that obtained with non irradiated ergosterol. In the 0.25%, 0.1%, 0.025% and 0.01% solutions of irradiated ergosterol the color responses were the same as those obtained with the same concentrations of non-irradiated. ergosterol.

The immediate and later results upon the ovaries and the uterus of the implantation of anterior pituitary substance, or of the injection of its growth-hormone into rodents (rat, mouse), as well as in dogs, has of late been extensively described in the literature. The acceleration of both the maturation of follicles and the formation of corpora lutea, as well as the hypertrophy of the uterine musculature under these conditions have recently been established by important experimental studies. (Evans, 1 Smith and Engle, 2 Zondek and Aschheim, 3 Putnam 4 ) All of these investigators agree concerning the stimulating effect of the hormonic principle on the tissues enumerated.

In the present study evidence has been obtained indicating that an overgrowth of the squamous epithelium covering the vaginal portion of the uterus can be initiated by means of either repeated intraperitoneal administration of extracts or by intramuscular transplantation of bits of the anterior lobe of the beef. Adult guinea pigs have been used in these experiments exclusively. In one series of our experiments, double ovariectomy was performed 2 weeks prior to the administration of anterior pituitary extract, for whose preparation I am under many obligations to Dr. E. M. K. Geiling.

The proliferation of the squamous epithelium on the outer surface of the cervix is shown by the development of epithelial prolongations, which in places extend deep into the connective tissue; but no epithelial pearls are found in these areas. Occasionally, the invading epithelial columns are fronted by a slight small cell infiltration. Mitotic figures are scarce. The histologic appearance is very characteristic. The ablation of the ovaries appears to promote this process of proliferation, as it is more pronounced than when the ovaries are retained.

When guinea pigs die in protracted anaphylactic shock, 1 death is usually preceded by a comatose condition with intermittent forced breathing and occasional convulsions. Sometimes this condition, in which the animals are insensitive to pain, lasts for several hours. These cases are suggestive that the comatose condition is produced by factors which are not present in the milder forms of the anaphylactic intoxication or in those cases where death occurs earlier after injection. The examination of the sugar content of the blood seemed indicated as the liver plays an important rôle in the production of protracted anaphylactic shock, also it is known that anaphylactic shock has a pronounced influence on the sugar content of the blood. 2 In addition in different bacterial intoxications hypoglycemia was observed. 3

The data given in the table are typical. Death, both in protracted anaphylactic shock and in tuberculin shock might occur with high, normal, or very low sugar values in the blood. In anaphylactic shock during the first 2-3 hours after the injection (also when the guinea pig dies in acute shock, or survives) the sugar content of the blood is increased. Later in the severe or fatal shock we find very low sugar values. This regularity was not as pronounced in tuberculin shock, probably because the stage and extent of the disease influences the reaction of the animal.

It is probable that the excessive hypoglycemia plays a rôle in the death of the animal. The occurrence of death both with high and with very low sugar values indicates that death is caused by different combinations of factors, both in protracted anaphylactic shock and in tuberculin shock.

The sugar determinations were made with the new method of Folin and Wu, 4 and in a number of cases we made parallel determinations, using the method of Hagedorn and Jensen. 5 The blood was taken from the heart before the death of the animal.

In 1906 Dale 1 demonstrated constriction of the cat's iris by ergotoxine and attributed this to direct stimulation of the iris sphincter. Recently Koppanyi 2 reported that a sufficient concentration of ergotamine injected intraocularly paralyzes the motor sympathetic terminations in the dilatator pupillae and stated that the abolition of sympathetic tonus was sufficient basis for explanation of ergotoxine constriction.

Our results of numerous studies on the isolated sphincter muscle of the iris in an oxygenated Locke-Ringer bath warrant the support of Dale's conclusion that ergotoxine constricts this muscle to a considerable degree. Ergotamine tartrate produces the same effect as ergotoxine. However, the results do not support the conclusions of Zunz, 3 Hess 4 and Poos 5 that ergotoxine causes this increased tonus by the parasympathetic route. Atropine in considerable concentration fails to “break through” the tonus elicited by ergotoxine and it does not prevent this tonus increase if applied before ergotoxine (Fig. 1).

In the intact eye of 7 cats, after recovery from light ether, ergotoxine miosis, produced by Koppanyi's intraocular method, was partially lessened by atropine intraocularly. The pupil of the eye thus treated did not correspond in size to the normal pupil of 7 mm. but was several millimeters smaller, indicating a direct action of ergotoxine on the iris sphincter muscle. (See Table I.)

To Mr. Eugene Marti of the Sandoz Company we are indebted for a liberal supply of ergotamine tartrate.

Ascariasis is a condition which has been recognized since the earliest medical times, and although it may cause little apparent disturbance the parasites are always a potential source of danger from migration into the various body cavities, from mechanical obstruction of ducts, the air passages, or the intestines, and from chemical intoxication. Between the latitudes of 35° North and 30° South there is a belt of ascariasis around the entire world. In the rural population of certain states of this country which lie in this belt, there is an incidence in certain areas as high as 48%, 1 while in other countries, such as China, as many as 90% of the population of certain regions have been found to be infested with these parasites. A great many substances and concoctions have been used for the removal of these worms, but they have all proven to be either inactive or dangerous. The two in most common use at present are Santonin and Oil of Chenopodium (or its active principle, Ascaridol). Both of these substances have been given to many thousands of patients without intoxication. On the other hand many sudden unexplained deaths have followed their use, which makes it impossible to predict what will be the outcome of their administration. Carbon tetrachloride and tetrachlorethylene, which are both very efficient against hookworm, are relatively ineffective against ascaris and may cause dangerous migration of these parasites. 2 We have, therefore, no safe or effective means of removing ascaris. On this account a search for a non-toxic ascaricide was begun several years ago in this laboratory, and a great number of experiments have been carried out on the physiology and pharmacology of this parasite.

In previous communications 1 , 2 , 3 it was shown that a vital dye, trypan blue, or a metal in the form of its salt, ferric chloride, when injected into the circulating blood stream rapidly accumulates in an area of inflammation, where the substance is fixed and fails to drain to the tributary lymph nodes.

Bowman, Winternitz, and Evans by microscopic studies 4 found that, in experimental tuberculosis, trypan blue injected intravenously stains tubercles in the liver. They pointed out the great affinity of giant and epithelioid cells for this vital dye, which was always found as granules within these cells. Lewis 5 found that if the cornea of a rabbit is inoculated with a living culture of the tubercle bacillus, a progressive lesion results characterized by an intense congestion of the conjunctiva. If the animal is given an intravenous injection of trypan red 24 hours or more after such inoculation, the fluid in the anterior chamber of the inoculated eye always becomes colored.

In view of the observation that iron, intravenously injected, accumulates in inflamed areas, a few experiments were set up to determine whether this metal when injected into the circulating blood stream would accumulate and be detected in tubercles.

Bovine tuberculosis was induced in several rabbits by the intravenous injection of 0.001 mg. of a saline suspension of Ravenel strain. From 4 to 5 weeks later extensive tuberculosis had developed in the lungs of most of the animals. These rabbits were given several daily intravenous injections each consisting of 5 cc. of a 0.25% solution of ferric chloride crystals. Three animals were killed after 3, 4 and 7 injections of ferric chloride. The lungs were carefully removed and dipped in acidified potassium ferrocyanide (3 parts of 1% HCl to one part of 2% K₄FE (CN)₆).

Atrophy, partial and complete, of the kidney of dove or pigeon can be obtained by section of one ureter. Pressure develops in the occluded duct and kidney, and insoluble urates later disappear from the contents of the duct. The uninjured kidney readily undergoes functional hypertrophy.

These observations have a bearing on the problem of the agenesis of organs. They indicate that in some cases the absence of a glandular organ which, like the kidney, is functional in the embryo may have been formed (not agenesis) and-through malformation or malfunction of its duct-later undergone complete atrophy. In contrast, section of the genital ducts of these birds was not followed by atrophy of testis or ovary; this evidence therefore indicates that the absence of gonads in birds has a different origin and significance.

It has been shown that fresh cabbage, steamed cabbage and cabbage from which 60% of its weight has been removed as press juice produce thyroid hyperplasia in rabbits when fed as their principal food. 1

It has also been shown that steamed hashed cabbage that has been kept exposed to air in a moist state for 4 to 5 days fully retains its goiter-producing quality. The goitrogenic substance was therefore heat stable and at least not readily lost when exposed to air in the moist state. As a further step in determining the nature of the goitrogenic substance in cabbage we have studied the effect of drying. No facilities were available for drying cabbage in vacuo in the amounts needed. Experiments were made with tested goitrogenic cabbage dried in 2 ways as follows:

1. Imported Holland winter cabbage was steamed for 30 minutes. The juice was pressed out under 450 lb. pressure and the pressed cake was then fed into an atmospheric double drum drier. Steam was introduced into the drums under 75 lb. pressure. The cabbage was in contact with the drums about 30 seconds and was automatically scraped off as nearly dry flakes. This material was at once transferred to covered containers in contact with solid CO₂ and kept over night, when it was stored in flasks and evacuated.

2. Northern New York winter cabbage (batch 21) was steamed for 35 minutes and 50% of its weight was removed as press juice. The leaves were then separated and put in trays in a current of air at room temperature. Drying was completed in about 36 hours and the product represented from 7 to 9% of the original whole steamed cabbage.

Further studies have been carried out in an effort to determine the nature of the goiter-producing substance contained in cabbage and other vegetables. 1 , 2

It was first considered advisable to attempt to find out whether or not this goiter-producing factor was soluble in water. Cabbage was steamed for 30 minutes, hashed and pressed until 50% of the total weight had been removed. The residue thus obtained had previously been shown 2 to contain a considerable proportion of the goiter-producing substance. Samples of this residue were washed with one and two volumes of water respectively, at room temperature and the water removed by pressing. As shown in the accompanying table, no marked change in the goiter-producing power occurred in either instance. Similarly, boiling the above residue for 15 minutes in 2 volumes of water, and pressing to its original weight did not materially alter its goitrogenic power.

Studies were then made of the effect on the goitrogenic power of cabbage of extracting with water at various hydrogen ion concentrations. The fraction which remained, after removal of 50% of the total weight as juice, from steamed hashed cabbage, was allowed to stand for 15 minutes at room temperature in 2 volumes of water to which sufficient hydrochloric acid had been added to bring the pH of the mixture to 3.0. The water was then pressed out and the residue fed to rabbits. Such a procedure invariably produced a definite increase in the goiter-producing power of the cabbage. Boiling the cabbage in 2 volumes of water at pH 3.0 for 15 minutes further increased its goitrogenic power. Boiling at pH 3.0 for 30 minutes gave no detectable improvement over boiling for 15 minutes.

The discovery by Chesney, Clawson and Webster 1 , 2 , 3 that cabbage when fed to rabbits as their principal food produces marked thyroid hyperplasia has provided a rapid and more practical method for testing various antigoitrogenic agents. Last year we showed that cabbage grown in the spring and early summer is much less goitrogenic than cabbage maturing in the late autumn. 4 Also it was pointed out that whole press juice and juice concentrates made from potent goiter-producing cabbage had little or no goitrogenic activity.

Further work showed that the goitrogenic activity of cabbage was in general inversely proportional to its ability to absorb iodine. This suggested that there were 2 substances in cabbage in variable amounts, one of which was goitrogenic and the other antigoitrogenic. This view is further supported by the fact that washing hashed, steamed cabbage with water increases its goitrogenic activity. Since the antigoitrogenic activity corresponds roughly to the amount of reducing substance (determined iodometrically), we have sought an available plant which contained the reducing substance in greater amounts than is ordinarily found in common vegetables. We have obtained very potent concentrates from the juice of skunk cabbage (Symplocarpus foetidus) and have found that it produces thyroid involution in rabbits in from 8 to 10 days when fed by mouth daily in amounts equivalent to 100 units (a unit being the amount of juice required to absorb one cc. of N/100 iodine) in addition to our standard stock diet of oats and alfalfa hay. Sterile fractions introduced intraperitoneally appear to be more effective. Fresh cut alfalfa and lawn grass also produce involution of thyroid hyperplasia when fed to rabbits in amounts of 300 to 400 gm. daily for 3 weeks.

Studies upon regeneration 1 have been carried out to test the hypothesis that persistent embryonic cells are responsible for the formation of new tissues during regeneration, and that the power or capacity for regeneration is to be correlated with the number of such cells present. It has been shown that in different species of planaria, cells of an embryonic type, called “formative cells,” undergo rapid proliferation after cutting the planarian, migrate to injured areas, and differentiate into the new tissues characteristic of the regenerating part. Species of planarians that exhibit the greatest capacities for regeneration possess the greatest numbers of these formative cells. Hickman 2 destroyed the capacity for regeneration by the use of X-rays and radium, and histological studies of such irradiated worms showed a selective destruction of these formative cells.

Other investigators showed that the rate of metabolism and of oxygen consumption in particular, increase immediately after cutting and remain at a high level throughout regeneration. The important rôle of glutathione in the establishment of the metabolic level and in the utilization of oxygen indicated that important correlations might be found between the processes of regenerative development and the quantitative distribution of this compound. Numerous workers have found glutathione in greater concentrations in the tissues of embryos and in adult tissues capable of continued cell division than in adult tissues in general. Recently Hammett 3 has shown glutathione to be a stimulus to cell division.

Using a modification of methods of Joyet-Lavergne 4 and Hammett 3 the glutathione content was determined in two species of Turbellarians, Planaria agilis, and Procotyla fluviatilis (Dendrocoelum lacteum). The former species possesses a high capacity for regeneration and shows a high concentration of glutathione; the latter, which exhibits a low capacity for regeneration, shows a lower content.

It has been found impossible to affect the carbon dioxide or total acid production of excised frog muscles by placing them in adrenalin solutions. 1 The absence of a calorigenic effect 2 under such unphysiological conditions was not surprising; and more recent work has indicated that the absence of the viscera 3 and particularly of the liver 4 may have been as responsible for the negative result as the lack of proper circulation or other abnormal conditions to which the muscles themselves were immediately exposed.

It is not known in what manner the viscera cooperate in the calorigenic action of adrenalin; whether by serving as the locus of its action, or by keeping the peripheral tissues in the proper physiological condition to respond to the adrenalin itself. The following experiments were undertaken to determine some of the effects that might be produced in one of the hind legs of an anesthetized cat upon the addition of a known amount of adrenalin, directly to its arterial blood supply.

All experiments were done on cats under chloralose anesthesia. The animal was always prepared so that simultaneous samples could be taken of the arterial blood going to and venous blood coming from the left hind leg. At the time of collection of the venous sample the rate of flow was also determined in a manner somewhat similar to that described by Himwich and Castle. 5 The usual precautions were taken to prevent alteration in the gas content of the blood; and this was determined by the manometric method of Van Slyke and Neill, using 0.2 cc. samples in duplicate.

In large cats that could stand the additional loss of blood, 2 normal sets of samples, 10 or 15 minutes apart, were taken before the adrenalin injection; these served to establish the average spontaneous variation to be expected under the conditions of these experiments. In the remaining experiments the adrenalin was injected immediately after taking a single normal pair of samples.

Many authors have tried to prove that the pancreatico-duodenal vein is the carrier of the pancreatic hormone but nobody was able to accomplish this for two reasons: (1) Blood was taken in artificial conditions of acute experiment; 1 (2) for detection of insulin no direct biological, but only unspecific and indecisive indirect tests 2 were used.

We obtained the blood from the pancreatico-duodenal vein of healthy dogs under quite normal conditions by means of angiostomical tubes. 3 For detection of insulin we used the most sensitive biological test of Brugsch and Horsters 4 —hypoglycemic reaction of blood accompanied sometimes by paresis or paralysis of the legs of fasting white mice after intraperitoneal injection of the analyzed blood.

In our experiments the blood drawn from the pancreatico-duodenal vein of fasting angiostomised dogs before and after intravenous injection of 25-50 gr. of glucose was introduced in amounts from 0.2 to 1.0 cc. into the peritoneal cavity of white mice. Two to 3 hours after injection the mice were killed by decapitation and their blood sugar evaluated by the method of Hagedorn-Jensen. The results show in a definite way that in a fasting dog insulin cannot be detected in the pancreatico-duodenal blood even with very sensitive biological tests. After intravenous injections of glucose considerable amounts of insulin are present in the blood of the pancreatico-duodenal vein. There was in literature and uncertainty whether insulin is secreted in an active or in an inactive state; our experiments prove that it is secreted into the bloodstream in an active state.

Contrary to the insulin secretion of the pancreas the epinephrine secretion by the suprarenal glands seems to proceed continual in a fasting dog. We have successfully applied the Brugsch insulin test in our experiments for the detection of epinephrine in blood, hypoglycemic reaction resulting instead of the hypoglycemic one.

Though tartrates have long been used in medicine, and grapes and grape products, the chief sources of tartrates are common foods, there is still much difference of opinion as to the effect and mode of action of tartrates in the human body. Among the unsettled questions are: 1. Are tartrates absorbed from the intestine? 2. If absorbed, are they oxidized in the tissues? 3. Are they alkalinizing? 4. If alkalinizing, how is this effect produced? Solis-Cohen and Githens, 1 Blatherwick, 2 Post, 3 and others believe tartrates are alkalinizing, the basis of their belief evidently being the idea of absorption and oxidation. Pickens and Hetler, 4 Wood, 5 Simpson, 6 Rose, 7 and others are on the contrary side of the alkalinizing question. Sollmann, 8 McGuigan 9 and others take a middle ground.

We can not tell whether tartrates are absorbed from the human intestine or not; but if they were absorbed in the case of any of our experimental subjects they were evidently oxidized, for we found no tartrates in the urine after their ingestion in quantities as great as 2 U. S. P. doses in a day's intake.

Rochelle salts, grapes, raisins and grape juice all proved to be definitely alkalinizing. Any of these substances, when added to an acid-forming diet, markedly decreased urinary acidity.

This alkalinizing effect of tartrates would be strong evidence of their absorption and oxidation, were it not for another process that explains this effect. In mixtures of feces and Rochelle salts, incubated at 37.5°C., the tartrate ions were decomposed within 6 to 24 hours. This proved true without exception in 15 cases.

In previous syntheses of aspartic acid the following reactions have been used: The decomposition of acid ammonium malate by heat, 1 the racemization of active aspartic acid 2 and active asparagine, 3 the reaction of maleic or fumaric acid with ammonia, 4 the reduction of oxalacetic ester oxime, 5 the reaction of silver fumarate or potassium acid fumarate with hydroxylamine hydrochloride, 6 the reduction of nitrosuccinic ester, 7 the catalytic reduction and ammonation of oxalacetic acid, 8 and the hydrolysis of the addition compound formed from sodium malonic ester and chloroacetic ester. 9

The present synthesis is believed to be more satisfactory than those previously reported for aspartic acid.

Phthalimido malonic ester, prepared from potassium phthalimide and bromodiethylmalonate, was converted to sodium phthalimido malonic ester by allowing it to react with molten metallic sodium suspended in toluene. A stable addition product was then formed as a dark colored oil by the reaction of chloroacetic ester with sodium phthalimido malonic ester. This product was readily hydrolyzed by hydrochloric acid with the formation of dl aspartic acid, phthalic acid, carbon dioxide, and ethyl alcohol. Side reaction products are not probable.

The acid hydrolysate was evaporated to precipitate the phthalic acid which was removed by filtration. Hydrochloric acid was removed by the addition of the calculated quantity of silver oxide to the boiling diluted diltrate. After removing the precipitate of silver chloride and evaporating the filtrate to a small volume d,1 aspartic acid crystals separated after standing for 3 days. Upon recrystallization from hot, 50% ethyl alcohol these crystals darkened and decomposed over the range, 311-325°C. Within the limits of experimental error they were shown to contain the theoretical quantity of amino nitrogen.

Under certain special conditions the rate of urea excretion in the urine is directly proportional to the blood urea concentration so that the ration Urine rate/Plasma concentration Becomes a constant. 1 Under these conditions this ratio varies only with the amount of functioning renal tissue 2 , 3 and can be used as an accurate method for measuring renal function in man. 4 It has recently been shown 5 in the rabbit that phenol red is excreted in a manner similar to urea in so far as the relation of the urine rate to the plasma concentration is concerned. This has led us to examine the possibility of using phenol red in place of urea in performing the Addis test of renal function 4 which has been referred to. The results presented in Table I which were obtained from a subject without renal disease after the injection of 1 gm. phenol red∗ during an urea diuresis indicate that it may be feasible to use phenol red in place of urea to determine the Addis excretory ratio. The difference between the urea and phenol red ratios which is apparently constant will be discussed elsewhere. There are certain advantages over urea in the use of the dye, particularly in the determinations in the plasma and urine. The actual concentrations need not be measured. After appropriate dilution and alkalinization the serum and plasma are compared in the 2 cups of a good colorimeter and the ratio calculated from the readings and respective dilutions. The clinical application of the use of phenol red in this manner is being investigated.

The inactivation of staphylococcus bacteriophage by methylene blue was reported by Schultz and Krueger. 1 Further tests in this laboratory with various samples of methylene blue∗ have given practically the same results, concentrations of 0.05% of the dye inactivating the bacteriophage within 24 hours. In higher dilutions longer periods of time were required for inactivation, whether the tests were carried out at room temperature or at 37°C. In only a few isolated cases was an inactivation obtained with concentrations below 0.005%, when the ordinary bacteriophage suspensions were used or when such suspensions were diluted 1-10 with Martin's broth.

Similar tests have been carried out with various other dyes including toluidine blue, methylene violet, methylene green, methylene azur, thionin, eosin B, and phenol red. These dyes were added in relatively high concentrations to bacteriophage filtrates which were then incubated at 37.°C. for 24 hours or longer and tested for lytic activity. Of the series tested in this way only one, toluidine blue, served to inactivate the staphylococcus bacteriophage.

Several individual samples of the same brand of toluidine blue† have given results which in all respects were similar to those obtained with methylene blue. When incompletely inactivated dye-phage mixtures were plated out with susceptible organisms a diminution in the number of plaques was noted, both in the case of methylene blue and of toluidine blue.

Tests were made with the dye-phage mixtures which were incubated in an atmosphere of hydrogen, nitrogen, or oxygen. The results obtained were identical with those described above, while controls incubated under the same conditions retained their lytic activity.

Inactivation was not obtained with either methylene blue or toluidine blue when added to an anti-coli bacteriophage.

Comparative anatomical studies of the heart in various mammals, with reference especially to the relation of the heart weight to the body weight, have yielded much interesting information. It was shown previously 1 that the heart of the racing greyhound averaged 13.8 gm. per kilo of body weight and stood at the top of the animal series in respect to relative heart size. It was also found that even the young greyhounds who had been confined to small kennels had relatively large hearts. Similar conditions but less striking figures were found in the study of the heart of the thoroughbred race horse 2 in which the average of 8.65 gm. of heart per kilo of body weight would indicate a similar change. This enlargement of the heart was present also in the young horses, colts and yearlings. The seasoned racers in both series had relatively enormous hearts. It was suggested that there was perhaps an inheritance of this acquired characteristic in the enlarged heart which had the capacity for even greater enlargement under stress. The factor of selection in breeding, however, was considered probable as a most potent factor. The greyhound heart averaged 5 gm. per kilo higher than did the heart of the ordinary dog, 13.8 as contrasted to 7.98. The thoroughbred's heart averaged about 2 gm. more per kilo than the ordinary horse's heart, 8.76 as contrasted to 6.77.

Opportunity was afforded for pursuing comparative anatomical heart weight-body weight studies on the animals that had to be sacrificed or died in the zoo, and thus was added interesting information on the question of the relation of heart weight to activity from another point of view.

This experiment was undertaken to determine the effects of large amounts of dog's gastric juice on a patient suffering with pernicious anemia. Castle and Townsend 1 previously had shown that 300 cc. of human gastric juice administered daily for a 10-day period did not improve the patient symptomatically nor produce any change in the blood picture. Because the amount of gastric juice secreted each 24 hours by man is far in excess of the 300 cc. used, it was thought worth while to repeat the procedure with larger doses.

For this experimental work pure, crystal clear dog's gastric juice was used. This was procured in large quantities from Dragstedt 2 at whose suggestion the experiment was performed. He had obtained the juice in a previous work by creating a pouch of the entire stomach of the dog in such a way as to avoid injury of the fibers of the vagus or of the blood supply. The analysis of the product showed a free HCl of 0.45%; total HCl, 0.5%; total chlorides, 0.55%, and pepsin 150 units.

The patient used in this experiment was Mr. S., Unit No. 18523, age 59, admitted to the Billings Hospital on January 20th, 1930, complaining of shortness of breath after slight exertion of 9 months'duration, numbness and tingling of his hands and feet, moderately severe nocturia and slight nausea following meals for a month preceding admission. These symptoms were associated with a progressive weakness during the past 5 months.

The physical examination revealed the following essential features: White male, apparently 65 years of age, with facial evidence of marked loss of weight, decided lemon-yellow tint of the skin and sclera and with only a slight impairment of the gait.

In continuing the study of the mechanism of pain in gastric and duodenal ulcer a method for increasing the gastric motility was desired. Bulatoa and Carlson 1 showed that the injection of insulin into normal fasting dogs increased the motility of the stomach. Quigley, Johnson and Solomon 2 concluded from their investigations that the same held true for the stomach of normal fasting man. Clinicians have frequently observed hunger as a symptom of the so-called “insulin reaction”. Hence it was assumed that the hunger so seen was due to the increased gastric motility, Carlson 2 having correlated “hunger pangs” with activity of the stomach.

This report is based on the results of 18 experiments done on 13 patients, 11 of whom had duodenal ulcer, 1 paroxysmal fibrillation, and 1 mild diabetes mellitus. The last 2 had a complete achylia to the histamine test. Kymographic records of gastric activity were made by means of the usual single balloon method connected to a water manometer, the entire system being inflated with 150 cc. of air. In a number of cases the position was checked by fluoroscopic examination. The tracings were all made with the balloon in the pyloric region of the stomach. Fasting periods ranged from 14 to 21 hours; the average time was 19 hours. The patients were instructed to register the appearance of “hunger pangs” by means of closing a switch set in series with a signal magnet.

In most instances control tracings had been obtained during previous experiments of a different nature. With those in which this had not been done, a preliminary period was recorded before the administration of insulin.

Insulin (Mulford) was given subcutaneously in doses of 8 to 20 units.

In the course of a study of the etiology of solitary bone cysts, a series of experiments was performed, the object of which was to infarct large areas of bone marrow and to determine whether or not a cystic degeneration takes place in these areas with formation of lesions similar to the solitary bone cysts of man.

The animals used were young and adult dogs. Under ether anesthesia and careful aseptic precautions, the periosteum over nearly the entire femoral shaft between epiphyseal lines was elevated, thus severing all blood supply and drainage. Small areas of periosteum were left intact near the extremities of the shaft to afford a ready source of blood supply for revascularization of the infarcted areas.

Twenty-four hours following operation no change was noted. Four animals sacrificed at various intervals from 4 to 8 days following operation show grossly infarction of the marrow of the shaft as evidenced by its pale dull yellow color in contrast with the red-brown appearance of normal marrow in the unoperated extremity. Near the epiphyseal lines are small sharply demarked red areas corresponding to the uninfarcted marrow beneath the small areas of intact periosteum. Microscopically, the marrow in the infarcted regions is necrotic, and the bony trabeculae well within the infarcted areas are dead. In the zone between infarcted and living marrow, there is, in places, a wide area of dense leucocytic infiltration, elsewhere the necrotic and living marrow are sharply demarcated without a zone of leucocytic infiltration.

A specimen studied 30 days after operation exhibited a porous cortex and red-brown normal appearing marrow in the metaphyses. In the upper portion of the shaft, the marrow cavity was filled by dense white fibrous tissue.

In the course of studies on the excretion of various chemicals by the liver, it was discovered that sodium salicylate and the sodium salt of diiodosalicylic acid did not appear in the bile of the rabbit in determinable quantities after the intravenous administration of 4 cc. of a 1% solution per kilo of body weight. 1 In view of the consequent discrepancy regarding the cholagogue and bactericidal action of salicylates on the biliary system, it seemed worth while to investigate the biliary excretion of salicylate in man. Three patients, 2 with drainage tubes in the common hepatic duct following cholecystectomy and choledochotomy, and one with a cholecystostomy, received by mouth a single dose of 20 mgm. of sodium salicylate per kilo of body weight. Samples of bile and urine were obtained before administration and after administration, namely 12, 40 and 79 hours respectively. The salicylate was determined colorimetrically by a modification of the Millon reaction. 2

Studies made in one case: Housewife of 66, cholecystectomy for chronic cholecystitis and cholelthiasis, choledochotomy for stones in the common duct, and catheter in the common duct. The bile and urine were collected in hourly samples for 12 hours. The flow of bile averaged about 26 cc. per hour (with a minimum of 8 and a maximum of 48 cc.) and totaled 290 cc. for the 12 hours. Sodium salicylate could not be detected. The urine totaled 1381 cc. for the same period. This contained a total of 0.584 gm. of salicylic acid, corresponding to 0.680 gm. of sodium salicylate.

Sodium salicylate did not appear in the bile in recognizable amounts following the oral administration of doses of 20 mg. per kilo of body weight to the 3 patients with disease of the biliary system.

The earlier studies of Fenn 1 and Gerard 2 on the oxygen consumption of frog nerve were not in complete quantitative agreement, even when differences in the experimental temperatures were allowed for. Fenn used American frogs (pipiens?) and a volumetric method, I used European species and a manometric technique, so it was desirable to ascertain whether the divergent results depended on material or methods. It also seemed useful to examine in more detail than previously the influence of various conditions on the rate of oxygen usage of nerve and to compare nerves of several animals. Observations carried on during 2 years by the Warburg technique are here summarized.

The Qo₂ (cmm. O₂ consumed per gm. of moist nerve per hour) of the sciatic of the American green frog, mainly R. pipiens, is lowest in December and January, Qo₂ = 37, and highest in June or a little earlier, Qo₂ = 60+. The Qo₂ shows a temperature coefficient of 2.2, as far as can be judged by experiments run at 18° to 24°C. The various American species do not consume oxygen at the same rate, but no accurate record of specific differences has been kept. The average Qo₂ of 227 experiments, mostly in the winter months, at an average temperature of 21.5 °C. for green frog sciatics in Ringer solution is 42, and the extreme variation is 20 to 80. Fenn's 3 latest value for these same frogs at 20°C., is 45, so our results, with different methods, are in agreement.

Any influence of various substances on nerve respiration is dependent on their ability to penetrate to the respiring regions. The great importanceof the perineurium as a passive barrier to diffusion, as described by Feng and Gerard 4 was not fully realized when most of these experiemtns were erformed; and some of the negative results obtained may have depended on the presence of the sheath.

During our studies of the effect of hemolytic amboceptors on different tissues the necessity arose for the creation of a standard for the comparison of the hemolytic index of different seras. Everyone who has worked on similar problems has no doubt encountered the disadvantages of the present system of plus symbols. Not only is it subject to the personal interpretation of the investigator, but the varying degree of the hemolytic index of a given serum will depend on the age of the serum and the temperature of preservation. Furthermore the following variants of the blood cells have to be taken into consideration: Condition of the animal at the time of taking the blood, methods of preventing coagulation, differential count of the different blood-elements, volume of the red blood-cells, time of centrifugation, temperature during centrifugation, and, the most important factor of all, the increased sensitivity of the red blood cells, which rapidly increases with the time of preservation.

In order to be independent of all these variants it was thought desirable to have a standard hemolytic chemical agent, the action of which might be compared with the hemolytic effect of a given amboceptor. For this purpose sapotoxin was prepared from Quillaja bark saponin (Merck, crude), following with minor variations the methods described by Kobert and Brandl. 1 Sapotoxin has the advantage of being more effective than saponin and the methods of purification guarantee a more uniform product than the different commercial saponins.

Two systems were prepared. The first one consisted, as ususal, of the hemolytic serum in varying amounts plus complement (guinea pig), plus 1 cc. of a 5% emulsion of red blood cells, which had been washed 3 times with a 0.85% NaCl solution.

In a recent series of papers by Anson and Mirsky, 1 the claim is made that hemoglobin, in N/20 HCl, is completely denatured in 3 minutes at 0°C. These authors claim, further, that this denaturation may be reversed to the extent of 75% by simply neutralizing the acid added with an equivalent amount of NaOH containing a small amount of NaCN. These experiments on the reversal of hemoglobin denaturation are, in essential details, substantially the same as those published almost 3 years earlier by Wu and Lin. 2 Wu and Lin, however, considered that they were dealing not with true denaturation but with a pseudo-denaturation which was peculiar to hemoglobin and dependent upon its prosthetic group. In order to test these divergent views, we repeated the experiments of Anson and Mirsky at temperatures which would really denature the protein. Instead of insolubility at the iso-electric point, we made use of precipitin reactions against a specific antiserum to follow the course of denaturation. Since true denaturation of a protein results in a gradual diminution of its ability to react with its antiserum, we may expect that any reversal of this denaturation would manifest itself by a return of its precipitinogenic properties.

A 3% solution of ox carbon monoxide hemogloibn, prepared by the method previously described by Boor and Hektoen 3 was used in these experiments. One volume of this solution was treated with 3 volumes of N/15 HCl and, after standing at room temperature for 10 minutes, the brown mixture was placed in a boiling water bath. At stated intervals, 4 cc. of this mixture was removed and neutralized by the addition of 1 cc. N/5 NaOH and 1/20 cc. N. NaCN.

Recently Burr and Burr 1 and McAmis, Anderson, and Mendel 2 have shown that the growth of rats on a diet from which all true fat has been excluded is distinctly inferior to that of rats on a diet which contains some fat, even though the fat used is devoid of vitamin A. Furthermore the health of the animals raised on the fat-free diet also suffers. Burr and Burr 1 believe that the total deprivation of food fat leads to the development of a deficiency disease, the symptoms of which are impaired growth, scaliness of the feet and tail, excessive production of dandruff, with ultimate hematuria and albuminuria, loss in weight, and premature death. In a later paper 3 Burr and Burr state that fat is an essential constituent of the diet because of the inability of rats to synthesize sufficient quantities of the more highly unsaturated fatty acids, specifically linoleic acid, for the maintenance of the normal functioning of the tissue lipids.

In the present paper the author wishes to present a few observations which would seem to have a significant bearing on the question of the rôle of fat in animal nutrition, especially with respect to the theory that linoleic acid and other highly unsaturated fatty acids are essential constituents of the diet. For the most part these observations are purely incidental, having been made on rats raised on various diets in connection with a study of phospholipid metabolism.

In the earlier phase of the work, all rats on experimental diets were raised individually in cages constructed throughout of No. 2 mesh wire screen and raised on 2-inch legs. Without exception, the rats which were being fed on the “fat-free” diet∗ developed a peculiar scaly condition of the tail similar in every respect to that described and illustrated by Burr and Burr.

Extremely severe hemorrhagic necrosis appears in rabbits at the skin sites prepared by an injection of a bacterial filtrate when the injection is followed 24 hours later by an intravenous injection (i. e., reacting factors) of a culture filtrate of the same or another bacterium. 1 , 2 , 3 , 4 Among the various phases of this phenomenon of local skin reactivity, the specific neutralization of the reacting factors by homologous immune sera was observed. A method has been described for quantitative measurement of the neutralizing antibodies of immune antimeningococcus and antityphoid horse sera. Inasmuch as the titer of these antibodies did not run parallel to the agglutination titer of the same sera, advantage was taken of this method 2 , 3 in order to develop highly potent neutralizing horse sera for ultimate therapeutic application. The work reported below was undertaken in order to concentrate and purify the antityphoid neutralizing antibodies.

Concentrated and purified antibody solutions should contain a maximum amount of antibodies associated with a minimum of total solids, especially of protein, as indicated by the nitrogen content. Gibson and Banzhaf 5 , 6 were able to obtain three to fourfold concentration of diphtheria and of tetanus antitoxins from antisera. Preparations of pneumococcus antibody solutions by methods of Banzhaf, 7 and Banzhaf and Sobotka, 8 and by other methods, yield concentrations up to 7-10 times the amount of protective units found in the original serum. It should be noted that only solutions containing the identical amount of total solids or nitrogen may be directly compared. By the following method we are able to reach a much greater concentration as demonstrated by the phenomenon of local skin reactivity to B. typhosus.

The present note calls attention to the possibilities of a new procedure in tissue grafting which promises to prove useful in investigation of problems in development and which should be made available to other workers in this field. The technique combines the method of grafting into the chorio-allantoic membrane as done by Willier 1 and others with that of skin transplantation as described by Danforth and Foster. 2

The writer is indebted to Professor P. D. F. Murray of Sidney for the information 3 that in his numerous experiments in chorioallantoic grafting he has at times included pieces of skin which occasionally produced down differing in color from that of the host. As suggested by Professor Murray such experiments are of much value in the study of potentialities in down production during the period of incubation. But they are limited by the fact that each automatically terminates with the hatching of the host and loss of its allantois.

With the hope of finding a way to overcome this handicap the following experiment was undertaken. Twenty-four White Leghorn eggs were put in the incubator at 12 M. on May 7. On May 9, at 3 P. M., 12 Barred Plymouth Rock eggs were put in the same incubator. On May 16, between 3 and 6 P. M., all of the Plymouth Rock eggs were opened but found to contain only 2 living embryos, one of which showed ectopic viscera and undoubtedly would have died in a day or two. These embryos were taken out in warm salt solution and grafts prepared from each. The transplants were made in the usual manner into the membranesw of 10 Leghorn embryos.

When the patency of the common bile duct is destroyed, as by a stricture, or by the pressure of an inoperable tumor of the head of the pancreas, the surgeon is confronted with an operation of necessity; an exit must be provided for the bile. Various procedures have been suggested, and are applicable according to the actual conditions found in the given case. The most usual procedure is the operation of cholecystenterostomy—a direct anastomosis between the gall bladder and some portion of the digestive tube.

This is a life saving procedure, easily carried out, with quite satisfactory results. Perhaps the only objection is that the pressure within the digestive tube is greater than the pressure in the gall bladder, with the consequence that the intestinal content is forced into the biliary system, with sometimes a final result of dilatation and general cholangitis.

This untoward final result of the accepted operative procedure led to the following: The intestine is sectioned at some suitable point, and the distal end united to the gall bladder by an end-to-end anastomosis (A) with the fundus of the gall bladder. The continuity of the digestive tube is now restored by a suitable end-to-side anastomosis of the proximal end of the tube to the side of the intestine at a point 7 or 8 inches below the end-to-end union between gall bladder and distal intestine (B). The purpose of this procedure is to interpose between the gall bladder and the stream of intestinal content a segment of intestine in which the direction of normal peristaltic activity would act as a one-way valve, tending to prevent the entry of intestinal content into the gall bladder.

Rats, fed the Steenbock and Black rickets-producing diet, were divided into groups at the time of weaning and exposed to sunshine and skyshine for varying lengths of time between 10:00 A. M. and 1:00 P. M. Diagnosis was based on line tests, roentgenograms, and blood phosphorus determinations. The duration of the experiments was usually 5 weeks, being prolonged when the controls did not show florid rickets within this time.

During June, 1929, an average daily exposure to sunshine of 3 minutes prevented rickets, during July 9.5 minutes and during October 5 minutes. The average daily exposure to sunshine is frequently less than the actual time out of doors because of cloudy weather. Since no indications of rickets were present shorter exposures would certainly have been sufficient. From November 16 to December 20, 1929, an average daily exposure of 10 minutes afforded protection but 5 minutes did not. From December 5 to January 17 rats given an average daily exposure of 14 minutes developed mild rickets, as did those exposed for from 2 to 5 minutes from January 17 to March 31. An average daily exposure of 6 minutes from March 29 to May 1, however, was protective.

During June, 1929, an average exposure to skyshine for 8 minutes daily was insufficient. During July, 24 minutes was borderline, and 48 minutes afforded complete protection. During October, November and December exposures of 22 to 24 minutes were protective, as was an average daily exposure of 67 minutes from January 3 to February 14. From February 10 to March 24 incomplete protection was afforded by 28 minutes'exposure, while 47 minutes during April was just borderline.

Such observations will be made for several years. Rats are also being exposed under some of the ultraviolet transmitting screens.

Groups of 2-week-old chicks, fed a leg weakness-producing diet, were exposed daily for 6 weeks to different amounts of sunshine and skyshine between 10:00 A. M. and 1:00 P. M. Growth was followed by weekly weighings. As judged by appearance, attitude, roentgenograms and blood calcium and phosphorus, an average daily exposure to sunshine of 4 to 5 minutes from October, 1929, through March, 1930, and of 2 to 3 minutes through April, 1930, prevented leg weakness. An average daily exposure to skyshine of 62 minutes protected the chicks from October, 1929, to the middle of February, 1930, 28 minutes sufficed from that time through March, 1930, and 23 minutes during April, 1930. We are confident that smaller amounts of radiation would have been effective. Better growth was obtained in the skyshine than in the sunshine animals from October 16 to January 10, indicating that the exposures to direct sunshine were, perhaps, too long.

From determinations of the number of red corpuscles, the quantity of hemoglobin, and the relative volume of packed red cells in any sample of blood it is possible to calculate the mean volume and the hemoglobin content of the red corpuscles of the sample. 1 The constants derived by these calculations are spoken of as mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular concentration. Mean corpuscular volume is expressed in cubic microns. Mean corpuscular hemoglobin refers to the actual amount of hemoglobin contained in the average red corpuscle and is expressed in micromicrograms. Mean corpuscular concentration refers to the hemoglobin contained in the red corpuscle in proportion to its volume. In the determination of this constant the red corpuscle is presumed to contain an aqueous solution of hemoglobin the concentration of which is calculated and expressed in per cent.

Some 400 accurate blood determinations have been carried out in 140 patients suffering from anemia produced by a large variety of causes. On the basis of differences in the size and hemoglobin content of the red corpuscles observed in these cases, 4 distinct classes have been differentiated:

I. The first and most obvious group, which can be called macrocytic, includes the cases of pernicious anemia, sprue, and a case of pernicious anemia of pregnancy. The noteworthy characteristic of this group is an increase in the mean size and hemoglobin content of the red corpuscles. The increases in corpuscular volume and in corpuscular hemoglobin are proportional and thus the normal hemoglobin concentration of the cells is not disturbed. The increases in size and hemoglobin content vary more or less inversely with the red cell count but this correlation is not entirely stict. 2

In the absence of oxygen nerve conduction is suspended in several hours, the activity of each fibre becoming gradually less until it blocks. Conduction has been shown to depend on oxidations, and the long persistence of activity with outside oxygen excluded to depend on the existence in nerve of an oxidizing reserve. The rapid recovficial action of Ringer on a nerve that has failed to recover from cold block. Finally nerves soaked in isotonic NaCl for 40 minutes before the start of asphyxia, though still fully recovering in oxygen, no longer show any recovery in Ringer. Nerves soaked in NaCl followed by Ringer behave as if they had been in Ringer throughout.

While there is good evidence to show that the virus travels along the axis cylinder of the nerve fibers of the spinal cord, particularly from recent work of Fairbrother and Hurst, 1 dissemination by the cerebrospinal fluid has been invoked in explanation by other authors. (Flexner and associates. 2 , 2 ) A crucial experiment to settle the question would be found in an attempt to recover virus from the cervical cord and from the lumbar cord of a monkey, inoculated intracerebrally, after complete transsection of the spinal cord above the lumbar region. Incidentally, further information might be adduced by histological examination of the 2 separate cord sections for the presence or absence of specific lesions.

Accordingly, we have carried out a complete transsection of the spinal cord in 2 monkeys, severing the structure at the level of the first lumbar vertebra. In the first animal (Monkey 144), 2 silk ligatures were tied tightly around the unopened dural sac, crushing the cord. The whole structure was then cut between the ligatures, the stumps retracting about 1 cm. apart. In the second animal (Monkey 165), the dural sac was opened, but not severed, and the cord was totally divided, leaving a gap of about 3 mm. The operative procedure in the first animal was adopted in order to test the possibility of dissemination by routes other than either the nervous substance or the cerebrospinal fluid, such as the general circulation or the lymphatics. In the second animal our main interest lay in distinguishing between transmission by the cerebrospinal fluid and through the cord itself.

The 2 transsected monkeys, which immediately after the operation showed a complete paraplegia of the lower extremities, including paralysis of the bladder and rectum, were infected intracerebrally the following day, together with 2 normal controls.

In the first observations made in this laboratory on the induction of feathering in capons and cocks subsequent to injections of chemically prepared hormone during the period of feather regeneration, regional variations in the degree of plumage responses became evident. It was noted that feathers having a more rapid growth rate required definitely higher concentrations of hormone for the female reaction than feathers having a slower growth rate. 1 The growth rates of feathers in various parts of the body have now been accurately measured, and constant regional differences have been established. The birds used for these experiments were brown leghorn fowls, and in this breed the capon is similar in plumage to the cock. In both cock and capon, the growth rate of the feathers is greater in the breast than in the saddle or back, and even greater in the posterior than in the anterior region of the breast. The ratio between the most rapidly and the most slowly growing feathers when measured in growth in length per day is approximately 2:1. In the hen differences in growth rate in various parts of the body are slight, and the general rate for all is intermediate between the maximum and minimum rates of the cock. The threshold concentrations of hormone required for the reaction are closely correlated with this observed difference in growth rate.

Feathers formed on a capon receiving regular effective daily injections of female hormone are completely female in character; if, however, the injections are restricted to short periods of time, then bars or patches of female color are laid down on an otherwise male type of feather. One single injection will, if sufficiently large to produce the threshold concentration, be recorded by the feather.