58 INTERNAL SECRETIONS 



We have seen that in many species the sexual characters are 

 fixed during ontogenetic development by the action of the 

 sexual glands, so as to acquire finally a relative independence 

 of the sexual glands. One might suppose that such a fixation 

 of sexual characters takes place also during phylogenesis; the 

 sex characters in such cases would be wholly independent of 

 the sexual glands. This hypothesis has been put forward 

 by Oudemans, in order to explain why the various species 

 differ from one another in the degree to which the formation of 

 the sex characters depends on the sexual glands. But Herbst 

 has pointed out, for good reasons, that in this conception one 

 is making the old mistake into which investigators who are 

 insufficiently influenced by evolutionist ideas so often fall . For 

 if the formation of the somatic and psychical sex characters 

 in the butterflies does not depend on the sexual glands, it 

 follows that we must look for other regulating factors. There- 

 fore, from the standpoint of the physiology of evolution, 

 nothing is explained by supposing a fixation by heredit}^ 



There are two groups of new facts which show how justifiable 

 Herbst's argument was. We know that in mammals the 

 sexual gland is by no means a homogeneous formation, and we 

 shall see later that the formative influence which the sexual 

 glands exert on other parts of the body is possibly not a direct 

 function of the generative part of the glands. And it may be 

 that the two parts, although endowed with such different 

 functions, are welded together in the mammahan sexual gland 

 into one organ, but are separated in some groups, such as the 

 Arthropoda. In the latter case a removal of the testicles or of 

 the ovaries, containing only the generative cells, will naturally 

 be without any influence upon the sexual characters. 

 Caullery (1913, pp. 128, 129), Harms (1914, p. 147), and lately 

 Courrier (1921) have also considered this possibility. Secondly, 

 the facts discovered by Goldschmidt (1917, 1920 a, 1920 b) in 

 moths are of great importance in this connection. In crossing 

 different species of the gipsy moth Goldschmidt obtained 

 different degrees of "intersexuality." The intersexuahty con- 

 cerned all external and internal sexual characters, and even the 

 sexual gland. Further, Goldschmidt stated that all the in- 

 dividuals which became intersexual turn from maleness or 

 femaleness into the other sex at a time which is constant for 

 a given combination of races. It follows from his experiments 



