2l8 
GENETIC STUDIES ON THE SILKWORM 
P86'i4 Moricaud-quail x A i8'i4 Plain 
I 
I I 
A12C/15 Moricaud Normal 
Pale-quail $ x J 164 161 
I 1 ; , , 
I i j 1 1 j 1 I 
Mor. Mor. Norm.(mPQi) Ou^mpQ 1 ) Mor. Mor. Norm.(PQi) Qu.(pC) 1 ) 
qu. + pi. -f-pal. qu. qu. + pi. -f-pal.qu. 
A478'i5 86 64 78 84 A476'i5 296 68 53 21 
M77' l S 195 67 55 22 
In the offspring of the crossings of pale-quail with normal, moricaud and 
striped, the light normal or light quail appeared in the majority of cases ; 
similar results came out in the crossings of plain with those epistatic forms 
named above. Hence it may be inferred that the majority of these epistatic 
parents have contained the lightest quail factor (ft 1 ) together with Q of a higher 
subtype [(Q? or Q,-» ). 
One may imagine this case to be an example of the "modification" of 
genes due to crossing (Gates, 191 5). But this seems improbable in the 
silkworm, (1) because the darker offspring are pigmented as intensely as the 
darker parent, i. e. no marked reduction of pattern development is recogni- 
zable, and (2) because there are at least certain cases in which no light normal 
or light quail appeared. 
The appearance of light normal and quail was also met with frequently 
in experiments on coupling and repulsion (Chapter IV) and the non-correlated 
inheritance (II, V): such cases are marked with In these cases I have 
distinguished the lighter subtypes from distinctly marked ones and counted 
the lightest normal and lightest quails with the plains and pale-quails respec- 
tively, because they agree in being destitute of Q, factor of the higher subtypes 
(Q s , ft 1 )• Heretofore the result of analysis on this way have been adequate 
and satisfactory. 
The light normal and light quails which appeared in the above crosses 
1) The families free from " ; ' r would have not been necessarily homogeneous in respeet of their 
plain and pale quail classes : in certain families it was not noticed if there were present some indi- 
viduals with lightest "eye-spots"; Mich families are involved within the non-asterisked group. 
