No. 600] EXPERIMENTAL IN TEE SEXUALITY 709 



be reported is the following : Both sexes contain the an- 

 lagen for either sex. In both sexes, irrespective of the 

 zygotic constitution, both anlagen might become patent. 

 Which one is to appear depends entirely upon the quanti- 

 tative relation of both. 3 If we apply the usual symbols 

 and keep in mind that the female sex is here the heter- 

 ozygous one we have the following formulae : 



[H|Mm = $, [Fr|MM = c?. 

 (It will soon be explained why the female set FF is put 

 in a square.) The female set as well as the male set act 

 independently and with a definite quantitative strength. 

 In order to have a convenient term we call this quantita- 

 tive value of the sex-factors their potency or valency. 



3 The idea that sex-determination is a quantitative rather than a qualita- 

 tive process is of course not new. Practically all writers about the cytology 



myself in 1904 ("Der Chromidialapparat, etc.," Zool. Jahrb^ \In.), 21) 

 and more fully developed in 1910 ("Kleine Beobachtungen, etc.," Arch. 

 Zellf., 6). Other such theories were proposed by R. Hertwig, 1905-07 

 ("TJeber das Problem der Sexuellen Differenzierung, etc.," Verhdlg. 

 deutsche Zool. Ges., 1905, 1906, 1907), based on his views about the nuclear- 

 plasmic relation. Again others of a Btrictly quantitative character were 

 discussed by E. B. Wilson ("Studies on Chromosomes," III, Journal Exp. 

 Zool, 3, 1906), by Th. Montgomery, Jr. ("Chromosomes in the Spermato- 

 genesis, etc.," Trans. Amer. Phil. Soc, 21, 1906), and by Th. Boveri 

 ("Ueber Beziehungen des Chromatins zur Geschlechtsbestimmung Sitzber. 

 physikal. medizin. Ges. Wiirzburg," 1908-09). A full discussion of the 



termination is given by Th. H. Morgan ("A Biological and Cytological 

 Study, etc.," Jour. Exp. Zool., 7, 1909), who decides for the latter. How- 

 former views. The first attempt to prove a quantitative theory of sex- 



practically the same as is to be used in this paper, combining the quantita- 

 tive view with the Mendelian and cytological results, has been developed on 

 an experimental basis in my papers from 1911 and 1912 {I. c.) and has 



Witschi). A third view has since been developed by Riddle in a series of 

 preliminary papers (Carnegie Year Book, 1913, Science, Vol. 39, 1914, 

 Amer. Natur., Vol. 50, 1916, etc.). His theory is based partly on chemical 

 studies of pigeon eggs, partly on hybridization experiments with doves. It 

 is not impossible that in the latter something like intersexuality is pro- 

 duced, if I understand the short accounts thus far published. 



