hiter^ial Factors of Sex Deter^nination 395 



Unfortunately for this case a reexamination of the problem by 

 Cuenot has lead to a contradictory result. Cuenot separated 

 the large eggs from the small ones by passing them through the 

 meshes of sieves of different sizes. The results appear in the 

 next table : — 



CUENOT'S TABLE FOR BOMBYX MORI 



There were no deaths in this set. It will be noticed that there 

 is a slight excess of males for the small eggs and of females for 

 the large eggs, which is in accord with Brocadello's hypothe- 

 sis, but the difference is too small perhaps to warrant one in 

 concluding that there is a definite relation between the size of 

 the egg and the sex of the moth. 



In another experiment, in which, however, there were some 

 deaths, the small eggs produced 119 males and 133 females, and 

 the large eggs 65 males and 108 females. 



Cuenot also found in the moth Ocneria dispar that one lot of 

 large eggs gave 14 males and 18 females. These results lend, 

 however, httle or no support to Brocadello's view. Wherein the 

 difference in the results lies is difficult to explain. It is hardly 

 possible that Brocadello's results can be accidental or erroneous. 

 Possibly the difference may lie in the fact that in the one case the 

 largest and smallest eggs laid by different individuals were com- 

 pared, and in the other case the largest and the smallest eggs of 

 the same batch were compared. If the eggs laid by different in- 

 dividuals differ in size, it is possible that the same difference 

 may extend both to male and to female eggs, hence accurate 

 results could only be hoped for by comparing the eggs of the 



