HISTOKY OF ENDOCRINE DOCTRINE 



III 



In the first half of the nineteenth century the accepted view of the phe- 

 nomena of secretion was that enunciated by Johannes Miiller, viz., that 

 the process consists of two phases secretion proper, or the casting out of 

 substances upon a' surface inside the body, as in the case of the gastric 

 juice; and "excretion/ 7 or the voiding of such secreted substances into the 

 external world, as in the case of bile or urea. This distinction was some- 

 what artificial, since bile, urea, and other excreted substances are also secre- 

 tions in the first instance. In 1801 the French physiologist Legallois, as 

 Gley has noted, surmised, from 

 the identity in composition of 

 all varieties of arterial blood and 

 the diversity of venous blood in 

 different parts of the body, that 

 this diversity is acquired, in 

 each case, from the loss of some 

 substance to the organ from 

 which the vein proceeds. Thus, 

 Bordeu's idea, A (arterial 

 blood) = 8 (secretion) + V 

 (venous blood), and Legallois' 

 idea, V (venous blood) = A 

 (arterial blood) 8 (secre- 

 tion), are identical. When A 

 and 8 are chemically known, A 

 being constant, V will be known ; 

 or, when A and V are known, 

 8 will be known. V is always a 

 variable. This remarkable intui- 

 tion of Legallois, like the hy- 

 pothesis of Bordeu, remained on a theoretical basis and was not put to ex- 

 perimental proof. In 1849 A. A. Berthold, a Gottingen professor, is said 

 to have transplanted the testes of a fowl to another part of its body, with 

 complete retention of its sexual characters, a phenomenon which he inferred 

 to be due to "the productive relation of the testes, i.e., to its effect upon the 

 blood and thence, through the corresponding effect of such blood, upon the 

 entire organism." This experiment and the apergu drawn from it are of 

 paramount importance, but Berthold's paper exerted no sensible effect 

 upon the physiology of his period. Nevertheless, the ductless glands were 

 coming to be known among the German physiologists as "blood vessel 

 glands" (Blutgefdssdrusen) or "blood glands" (Blukdrusen), and were re- 

 garded by the histologists Henle and Kolliker as preparers of different 

 chemical substances, which are utilized by the organism through the blood. 



Fig. 6. Arnold Adolph Berthold 

 (1803-1861) 



