Internal Factors of Sex Determination 395 
Unfortunately for this case a reéxamination of the problem by 
Cuénot has lead to a contradictory result. Cuénot 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 
SMA.L Eccs Larce Eccs _ 
Male Female Male Female 
I set 23 16 19 82 
2 set 43 36 31 26 
3 set 46 53 9 9 
4 set 24 24 6 35 
138 129 125 132 
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. 
Cuénot also found in the moth Ocneria dispar that one lot of 
large eggs gave 14 males and 18 females. These results lend, 
however, little 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 
