CALVIN B. BRIDGES 



647 



very accurately, so that a stock of tiny-bristles was carried along in the 

 easiest way by breeding tiny-bristle males to their heterozygous 

 sisters. Tiny-bristle females were found to be so infertile that they 

 could not be depended upon. One of the parents of such a stock 

 culture was a female carrying in one X chromosome tiny-bristles, 

 garnet, and forked, and, in the other X, sable-duplication, sable, and 



garnet 



\ tb K f/ 



The other parent was a male carrying sable- 



TABLE I 

 S 



0_ffspring of Garnet Female, Constitution 



itutionl ), 



th g fj 

 Male, Constitution (S g /). 



and Garnet Forked 



Feb. 14, 1916. 



Offspring of Garnet Female, Constitution 



TABLE II 

 S - 





S 5 



Forked Male {S th g f). 



and of Tiny-Bristle Garnet 



Mar. 9, 1916. 



duplication, garnet, and forked ( S g f ) . The offspring of this pair 

 were of the expected kinds and frequencies (Table I). No lethal 

 was present. 



For the next generation a garnet female was crossed to a tiny- 

 bristle garnet forked brother. The offspring showed that this m.ale 

 had received sable-duplication from the mother as the result of cross- 

 ing over, and was of the constitution S tb g f . The mother was 

 expected to carry sable-duplication, sable, and garnet in one X and 



