146 THE SEX-COMPLEX 



Development nucleus becomes broken up by branching septa of 

 s * ingrowing connective tissue, which divide the ovary into 

 a mesh-work of compartments. The tunica albuginea is 

 formed by the meeting of these septa beneath the capsular 

 epithelium. The indifferent cells enclosed in the con- 

 nective tissue mesh-work are believed to form secondary 

 oogonia ; but ultimately most of these degenerate, and 

 the spaces they previously occupied in the mesh-work 

 of connective tissue become filled by ingrowths from the 

 septa. The interstitial cells of the ovary, like those of 

 the membrana granulosa surrounding the surviving ova, 

 are derived from the connective tissue stroma. In these 

 circumstances, of course, the genital tubules outside the 

 gonad atrophy, and their remains may be recognized, 

 extending from the hilum of the ovary through the 

 mesovarium into the mesosalpinx, as the epoophoron. 



It is not difficult to understand, then, that, if there 

 be any hesitancy in the primary determination of sex, 

 seminal tubules may commence to develop in the 

 epithelial nucleus, even though they do not become 

 functional in the ordinary sense of the word, and that 

 the testicular interstitial cells may develop around them. 

 But if, in these circumstances, masculine genital cells 

 are absent and female are present the interstitial cells 

 around the tubules cannot arise from genital cells, nor 

 can there be spermatogenesis. 

 Unilateral One great difficulty, so it appears to me, and one 



aphroditism. which requires further elucidation, is why an ovitestis 

 may be found on one side in these conditions, and 

 not on the other. In this connexion it is interesting 

 to recall the fact that in ' true hermaphroditism ' 

 (ovitestis) in birds, unilateral distribution of the sex- 

 characteristics in regard to the plumage has been 

 observed by Poll 1 , Bond 2 and others. It must be 

 remembered, also, that in hens the right ovary and ducts 

 atrophy. Nevertheless, the plan of development 

 described above almost negatives the possibility of the 



1 Poll, H., Sitzb. d. Ges. Naturf. Freunde, Berlin, 1909, p. 331. 



2 Bond, C. J., Journ. Qenet., 1914, vol. iii, p. 205. 



