252 EdmundB. Wilson: 
accords with the facts. Obviously, therefore, the female or the 
male condition of the zygote will be established according to the 
kind of spermatozoon which enters the egg. The alternative is to 
suppose that the number and the size-relations of the chromo- 
somes in the zygote have no relation to those of the gamete- 
nuclei; but this is opposed by so great a body of experimental 
evidence as to be in the highest degree improbable. 
EGG SPERM ZYGOTE CAMETES 
nn 
I. Proltenor Type ® 
Fig. 2. 
In its detail, the conclusion thus reached is the reverse of 
Me Clung’s assumption, but nevertheless proves his hypothesis 
to have been correct in principle. That the spermatogonial number 
