386 Experimental Zoology 
more young in a litter than the poorly nourished. Putting to- 
gether all those cases where more than nine young were present 
in a litter, which indicates favorable parental conditions, there 
were produced 49 females and 43 males. Where fewer than 
g were born there were 62 females and 71 males. Although 
there is a slight excess of females in the former and of males in 
the latter cases, the numbers are so nearly equal that the influ- 
ence of nutrition cannot be said to be apparent. It may be 
noted that when more young are present the conditions for 
each are poorer, yet, in fact, more females were born. 
Schultze has carried out some experiments with white mice. 
One lot was starved. They were long in reaching maturity, 
and weighed only a half to a third as much as well-fed mice. 
This lot produced 4 males and 4 females. Another lot pro- 
duced 42 males and 48 females. Clearly there was no effect of 
nourishment to be seen. Schultze also examined the product 
of the second generation of starved mice, some of which were 
also starved and others fed. He obtained 36 males and 43 
females for the starved ones, and 20 males and 28 females for 
the well-fed individuals. He also paired poorly fed males with 
well-fed females in order to see if, as has been claimed, the better- 
fed parent would determine the sex. Well-fed females paired 
with well-nourished males gave 46 males and 36 females. The 
same females were then paired with poorly nourished males and 
gave 38 males and 37 females. Again there is no evidence of the 
sex being determined by the condition of the parent. 
Schultze also tried the effects of feeding mice on foods that 
were rich or poor in albumen. Potatoes and bacon were used 
as having little albumen, but on this diet the animals did not 
reach sexual maturity. Fed on white bread and water, they gave 
18 males and 22 females. For a food rich in albumen, tropon * 
was used, also other food rich in albumen, along with salt and 
milk. There were produced 29 males and 26 females. 
These experiments go far toward establishing the view that 
1 Tropon contains 21 per cent albumen, 60 per cent carbohydrates, and 15 
per cent fat. 
