SECRETION PHYSIOLOGY. 303 



process of the formation of substance by the gland cell — a dif- 

 ferent process, but one at present included under secretion — I 

 propose the name " Hylogenesis " (Gr. l»/-/^ matter and yhiat:: 

 generatiori)^ and for the substances formed the name '' Hylogens." 

 Thus trypinogen, mucinogen, pepsinogen are hylogens. The 

 secretions consist of the hylogens plus water, salts and other 

 substances derived unchanged from the blood. The present 

 paper deals solely with secretion proper. Hylogenesis is con- 

 sidered elsewhere."^ This word seems to me preferable to that 

 of " Mesastates," suggested by Mr. J. N. Langley. Ranvier^" 

 and Van Gehuchten"^ wish to call the process here named hylo- 

 genesis, "• secretion." This seems to me inadvisable, as thereby 

 cellular secretion would correspond with glandular rest. 



The experimental work embodied in this paper has been 

 carried on chiefly in the Physiological Laboratory of Columbia 

 University, and I am particularly indebted to Professor Curtis 

 and Professor Lee both for extending to me facilities of the 

 laboratories and for suggestive criticism. A portion of the 

 work was done in the physiological laboratories of Cam- 

 bridge University, England, and Marburg University, Germany. 

 I desire to express my hearty appreciation of the courtesy of 

 Professor Michael Foster and Professor Kossel in placing the 

 facilities of their laboratories at my disposal. To Mr. J. N. 

 Langley I am indebted for critical suggestions. 



II. SYMPATHETIC SALIVARY SECRETION. 



Stimulation of the upper end of the divided cervical sympa- 

 thetic nerve of the cat, horse, dog, sheep or rabbit generally causes 

 a secretion from the salivary glands. This secretion has every- 

 wheref the same characteristic features, indicating that it is pro- 

 duced in all salivary glands in the same manner. These com- 

 mon features are the following : The saliva reaches its maximum 

 rate of flow in the first lO or 20 seconds, and then generally 

 ceases, although stimulation lasts for several minutes. If sev- 



* Shortly to appear in the Journal of Morphology. 



f Except in the resting parotid and submaxillary glands of the dog. See next 

 page. 



