INTKODUCTION 5 



opposite. Neither is it feasible, as Schafer himself points out, to classify 

 internal secretions as exciting or depressing. Epinephrin, regarded by 

 many as the best known of the hormones, excites some tissues and de- 

 presses others. For example, in small quantities, it causes the blood 

 vessels of the skin to constrict, while those of the underlying muscles 

 dilate. Moreover, the effect of epinephrin in certain tissues may be 

 either excitation or depression, depending upon the amount used. Thus, 

 although moderate concentration of this substance passed through the 

 blood vessels of skeletal muscles cause augmented venous outflow, larger 

 quantities result in a diminished flow. A similar reversal of effect with 

 change of dosage, has been reported in the lungs. 



The attempt to meet the difficulty by the assumption that the process 

 is actually excitation in each instance, in the one case augmenting, and 

 in the other depressing mechanisms being involved, will scarcely ap- 

 peal to the thoughtful reader. It merely raises the much debated question 

 as to the nature of inhibition. If, as Verworn has maintained, inhibition 

 amounts merely to continuous subminimal stimulation, there would be no 

 need for the word chalone. 



Similar criticisms are to be offered against Biedl's division of all 

 internal secretions into "erregende" and "hemmende," i. e., exciting and 

 depressing. The same may be said of Livon's division of the hormones 

 into "hypertensive" and "hypotensive." Under different conditions the 

 same substance, for example, epinephrin, may be either exciting or de- 

 pressing, hypertensive or hypotensive. 



As descriptive of the tissues producing internal secretions, Matthews 

 has used the word "cryptorrhetic," meaning a with a hidden flow." Since 

 the term has the same practical significance as the better known "en- 

 docrin," it would seem that its adoption would merely serve further to 

 complicate the situation without improving it. 



Among certain American writers the term "endocrines" has come into 

 a certain vogue as a generic appellation to include all the organs of in- 

 ternal secretion. Etymologically the term is not a happy one, being an 

 adjective made to serve as a noun, just as "humans" is sometimes care- 

 lessly used as a synonym for "human beings." It is to be hoped that 

 the term will be discarded. 



Similar carelessness as regards linguistic niceties has resulted in the 

 introduction of such Greek-Latin hybrids as "adrenalemia," "suprare- 

 nalemia," and "adrenalectomy." "Epinephrinemia" and "epinephrec- 

 tomy" are scarcely more formidable and are etymologically much to be 

 preferred. 



The terminology as regards specific internal secretions is somewhat re- 

 dundant. For the suprarenal hormone we have epinephrin, a term first 

 applied by Abel, though to a benzoyle addition product rather than 

 to the specific principle itself. Among more punctilious American 



