THE DETERMINATION OF SEX 199 



possibly the most potent. This factor may be 

 conceived to act either upon the parent previous 

 to the maturation of the germ-cells, upon the germ- 

 cells themselves, or upon some susceptible embryonic 

 stage of the life cycle subsequent to that of the fer- 

 tilized egg. 



It has been suggested that since the egg is char- 

 acterized by possibly a more advanced metabolic 

 condition than the sperm due to the presence of the 

 nutritive yolk, consequently the more yolk or nutri- 

 tion there is, the more femaleness will characterize the 

 egg. In other words, femaleness is a nutritive condi- 

 tion associated in the egg with the presence of yolk. 



A generation ago Professor Schenk of Vienna, by 

 controlling the nitrogenous diet of certain royal 

 prospective mothers, gained a soothsayer's reputa- 

 tion as a prophet of sex which was based upon several 

 correct predictions. 



Of course, any prediction of sex is bound to turn 

 out correct in 50 per cent of the cases, regardless of 

 what it is based upon, since in man the two sexes 

 are approximately equal in numbers. Adherents 

 of all sorts of theories, therefore, have always been 

 able to produce considerable "evidence" to sub- 

 stantiate their speculations, however crude the latter 

 have been. 



Statisticians have pointed out that in times of 

 unusual hardship, like famine or war, when the 

 amount of available nutrition for pregnant mothers 

 is presumably reduced, there seems to be a prepon- 

 derance of males born. 



