Q-f! HEREDITY IN BABBITS. 295 



expectation is 27 normals and 27 albinos. Each hybrid tested 

 produced both kinds, usually in the same litter, but, curiously 

 enough, H 8 x A 2 gave in the first litter 5 young all albinos, 

 while in the second litter there were 6 normals and 2 albinos, 

 instead of the expected 4 of each. It will be noted that H 8 

 was the individual which gave a deficiency of albinos in the 

 4 succeeding litters when mated with H 10. The individual 

 matings were as follows : — 



Table 12. 



Hybrid Normals x Albinos (F^). 



Matings. Normal. Albino. 



Ho X A2 2 2 



H 5 X A 2 4 1 



H 5 X A 2 3 4 



H 7 X A 2 .{ 4 



H 8 X A 2 5 



H8xA2 6 2 



A 3 X H 10 4 2 



ASxHlO 2 5 



A3xH12 1 4 



Total 25 29 



2 normal hybrids of the first generation mated with one of the 

 original normals produced 20 youngs all normals. The matings 

 were N 1 x H 12, producing 11 young in 2 litters, and 

 N 1 X H 10, producing 9 young in 1 litter. The Mendelian 

 expectation is, of course, all normals. 



(c) Third Generation (F3). 



The albinos of the second generation extracted from the hybrid 

 normals of the first generation bred true when mated with one 

 another and with other albinos, in accordance with the Mendelian 

 expectation. 4 extracted albinos mated together and with 2 other 

 albinos produced 21 young, all of which were albinos. The 

 matings were as follows : — 



