6 R G. HOSKINS 



writers this term is most often employed. By others, however, it is little 

 used. The term adrenalin has come into most common use in the sci- 

 entific world at large, despite its having been adopted by a pharmaceutical 

 house as a trade name. Adrenin, which would seem to be most satisfactory 

 in point of simplicity, has had a certain vogue among British and Ameri- 

 can writers, but seems to be employed less frequently now than formerly. 

 A fuller discussion of the terminology on this point will be found in the 

 chapter on the biochemistry of the suprarenals. 



As regards generic terms for other endocrin substances, there is little 

 uniformity, and little is to be expected until the individual hormones 

 are isolated and chemically identified. Thyroxin has recently been in- 

 troduced by Kendall as a term to designate the active principle of the 

 thyroid gland. He has claimed and the claim is being gradually recog- 

 nized that this substance is the actual thyroid hormone. Other terms 

 for this are discussed in the chapter on the chemistry of the thyroid. 

 The pharmacologically active constituents of hypophyseal extracts are 

 fairly generally known as pituitrin and hypophysm, but there is no defi- 

 nitely accepted usage on the point. Final adoption of a satisfactory term 

 will probably wait upon the actual isolation of the substance or sub- 

 stances ; these the discoverer will have the right to christen as he sees 

 fit. For many years spermin has been in use as vaguely indicating the 

 hormone of the testis. Although the substance is recognized as a definite 

 nitrogenous body, there is little reason to suppose that it represents the 

 true internal secretion of the gonads. Numerous other terms are in use 

 as designating assumed "active principles" of the various endocrin or- 

 gans. For the most part the meaning of the terms is obvious. Until the 

 bodies referred to are actually isolated and chemically identified the 

 terminology in such cases is necessarily provisional. 



The Endocrin Literature 



To the physician or biologist who has not had occasion to make a 

 special study of it, the magnitude of the present-day literature on the 

 glands of internal secretion is probably not suspected. Interest in the 

 subject extends through all fields of animal biology, as well as to all 

 branches of clinical medicine. At the present clay important contributions 

 are appearing in a dozen languages in hundreds of different medical 

 and scientific journals and books. 



Until about 1800 relatively few articles of interest in this field had 

 been published. A great stimulus to the study of the glands of internal 

 secretion was afforded by the epoch-making work of Brown-Sequard on 

 testicular extracts. Although the work in" itself ultimately came to be 

 regarded as of dubious immediate significance, it aroused world-wide in- 



