On the mechanism by which water is eliminated from the blood capillaries in the active salivary glands

1. There is a spontaneous flow of lymph from the quiescent parotid gland of the horse. The quantity is never great but it was evident in all of our nine experiments. It is probable that part of the lymph that flows from the neck lymphatics in an anesthetized dog with all the salivary glands at rest comes from the salivary glands. This fact necessitates a limitation of Asher's theory of lymph production.

2. When the parotid of the horse is thrown into activity by stimulation of the cranial secretory nerves or by injection of pilocarpin into the blood there is no appreciable increase in the output of lymph from the gland as compared with that from the gland at rest. This is true both of the spontaneous flow and of the flow aided by direct massage of the gland.

3. The activity of the submaxillary does not appreciably influence the Row of lymph from the neck lymphatic in the dog. This conclusion is based on experiments on thirteen dogs. If the activity of the submaxillary gland increases the output of lymph from the neck ducts, the increase is too slight to be detected by our present method, and is not one-tenth of the saliva eliminated by the gland, as Barcroft's observations would seem to demand. Our experiments were made on the spontaneous flow; on the flow aided by movements of the lower jaw by a mechanical contrivance to secure absolute uniformity in rate and amplitude; and on the flow aided by direct massage of the head and neck by kneading. Moreover a check was introduced by way of recording the lymph flow from both neck ducts, while the submaxillary gland on one side only was thrown into periodic activity by chorda stimulation. As our results are directly contrary to those of Asher and Bainbridge, the question should be reinvestigated by others.