714 



THE AMEBIC AN NATURALIST 



[Vol. L 



I think these facts alone would be sufficient to prove 

 that the above given quantitative conception of sex-de- 

 termination is the right one. But we can quote further- 

 more a real experimentum crucis. We have seen that the 

 very weak European race F crossed with the medium 

 strong Japanese males Gr give a fairly high grade of 

 intersexual females. In our diagram of the values of e 

 we might put them at the point — 10 (Fig. 2) . The same 



weak females crossed with the very strongest males A 

 gave nothing but males, the would-be females standing 

 now on the point, say — 25. Now the strongest of the 

 weak races in regard to FF, i. e., the Japanese race K, 

 gave with these same males G slight female intersexual- 

 ism, say at point +15. If our conception is right, the 

 same females, crossed with the very strong males A, 

 ought to give medium intersexual females, to be put at 

 the point 0. And this is the actual result. 6 



Now we have reached a point where we want to know 

 how the complexes |FF| and M are inherited. Anybody 

 familiar with Mendelian analysis knows which results are 

 to be expected if F and M are independent Mendelian 

 factors. These tests, so far as fertility allows them to be 



organs based on our material is pictured in the paper of Poppelbaum 



given in my paper of 1914. In regard to the occasional appearance of a 

 single normal female in cultures where all females are transformed into 

 males, see our publication in the Proc. Nat. Ac. It was supposed that they 

 originated from a case of "non-disjunction." Their behavior in breeding 

 does not agree with this supposition but suggests another explanation, which 



in nature. Details can not be given without a lengthy discussion. 



olt might be added that a similar experiment can be performed with 



