42 EK. W. SEXTON AND M. B. WING. 
The proportions of Black to Red in these H. x H. experiments are about 
right if Exp. 106a is not counted. 
The H. male in this experiment had been previously mated with a Red 
female, and had had one brood of 9 young, | Black and 8 Red—a pre- 
ponderance of Red. 
The H. female had also been previously mated with a Red male, and 
had had 84 young in 3 broods, 32 Black to 52 Red, a preponderance of 
Red. When mated together the one brood of 52 was the result, 48 Black 
to 4 Red—a preponderance of Black. (The Red male with which the H. 
female mated was tried with another H. female which had already had 
30 young, 16 Black and 14 Red—with the result, one brood of 18 young 
hatched, 15 Black and 5 Red.) 
A great many of the F, animals from these experiments were mated 
in order to see if the results would repeat those already obtained in the P. 
F, and F, generations. They were examined regularly, but only a few 
records were kept, the fact that in all cases they bred true being con- 
sidered sufficient evidence of accordance with the Mendelian law. 
SEX. 
All the broods were kept in separate bowls to come to maturity, in the 
hope of finding the number of males and females hatched, and if the 
number varied in the different crosses. Owing to unfavourable conditions, 
bacteria, etc., it was found impossible to get good results. The broods, 
therefore, are taken in which over fifty per cent of the young came to 
maturity, and the numbers are given below, together with the broods in 
which less than fifty per cent survived, and the number of broods which 
failed entirely. 
As a rule, all or nearly all the animals in the small broods survived, 
probably because they were stronger, as they were certainly larger than 
the others on hatching. Almost all the very large broods failed in spite of 
repeated efforts to save them by separating them into several bowls so as 
to avoid overcrowding, ete. 
Of the broods that failed entirely 5 were in the P. x R. cross, 11 in the 
R. x P.; 29 in the H. x R., and 23 in the R. x H., 68 im all. 
