Production of transplantable growth

After analyzing the known numerous theories on the origin of abnormal growth and especially of malignant growth, which have been devised either with or without reference to facts, it seems possible to concentrate the apparently necessary postulates for the successful origin of abnormal growth to the following conditions which cover all important theories on this subject. The presence of a cell group in an indifferent stage of growth, the dissociation of this cell group from its surrounding and its change from the indifferent stage of growth to a stage of proliferation, the inflammation of the connective tissue, neighboring this cell group, and a changed metabolism of the cells, in which this cell penetrates and which it destroys. Supposed these conditions are true to actual facts it must be possible to produce experimentally these factors either in various sequence or all at once and observe results.

I. Embryonic tissue of the chicken heart, after twelve days'rncubation, was cultivated in a plasma medium for three days, and three 1 mm. square pieces implanted subcutaneously into a chicken. The implants produced after ten days small protuberances. Sections show cyst formation, caused by the isolation of the epidermis above the implants and inflammatory proliferation of the connective tissue of the host. Cyst formation, destruction of the feather follicles and accessory apparatus of the feather after previous isolation of the feather-forming complexes are visible. The implanted embryonic heart-muscle tissue which is surrounded by lymphocytes and newly formed connective tissue cells shows no considerable development. Protuberances produced in the same manner disappear after three weeks, as was to be expected.

II. The size of such a growth can be enlarged by a few injections of a growth-promoting substance, i. e., tetheline, into the protuberance itself.