gametic: coupling and repulsion in the silkworm. 



123 



larvae were all white-bl.u.d. d iiM.-u.l of l«-in- yellow-blooded, and the normal- 

 patterned were all provided with yellow blood instead of being white-blooded. 

 As the parental formulae are known to be ssNNyy (Aqjiku) and SsnnYy 

 (S. 5. Ml striped yellow) respectively, we should expect, if the inheritance 

 was normal, the offspring to be as follows : 



1 SnYsNy Striped yellow 



1 SnysNy Griped white 



1 snYsNy 7^°* 



1 snysNy formal white 



forced 

 larking 



ly stated such wa 



s not the case. 



Therefore we ; 



here occurs a per: 



feet repulsion bet^ 



veen the stripet 



lour. The case n 



lay be diagramat 





1 









ssNNyy 



SsnnYy 



Gametes 



sNy 



Sny, snY 











SnysNy 



snYsNy 



Ratio 





1 



Observed 



63 



65 



Expected 



64 



64 



I have had only one mating of this cross. But there seems to be no 

 way of explanation other than that there takes place an absolute repulsion 

 between stripedness and yellowness. Moreover, it is highly probable that the 



