56 



INHERITANCE IN RABBITS 



It is represented in our gray ^2071, which, when mated with a sooty yellow 

 female (9 1414), produced 4 gray and 3 yellow young. This variety is repre- 

 sented likewise by 9 175 and $ 176, borne by the Belgian hare (9 431) in a 

 mating with the old yellow lop male. 



Female 175 was not actually mated with a black rabbit, but, had she been 

 capable of producing black offspring, she should have done so in the matings 

 with 3 177, a rabbit that did produce black young. Male 176 was mated with 

 two does known to be capable of producing black offspring, with the result 

 shown in table 34. 



TABLE 34. Matings and young of c? 176, gray. 



(6) A sixth variety of gray rabbit produces gray, black, yellow, and sooty 

 yellow offspring, but none of the other colors. It is heterozygous both in E 

 and in A. It differs from variety 5 only in being heterozygous instead of 

 homozygous in A. It may readily be produced by crossing yellow with black, 

 or gray with sooty yellow, the result of these two crosses being identical. The 

 formula of this variety is B 2 Br 2 E(R)AC 2 I 2 U 2 Y 2 . This variety is represented in 

 our gray rabbits (c? 177 and 9 178), which were borne by the Belgian hare (9 431) 

 in the same litter as the rabbits of variety 5 already described, viz, 9 175 and 

 c? 176. Another rabbit of this variety was the gray cf 505. 



TABLE 35. -- Matings and young of c? 177, gray. 



Why rabbits 177 and 178 should differ in breeding capacity from their brother 

 and sister, 176 and 175, is readily explained. The father was heterozygous as 

 regards factor A. To 175 and 176, he transmitted it; to 177 and 178, he did 

 not. But all four received this factor from their mother, a homozygous gray 

 rabbit (9431). Hence 175 and 176 were double in A, but 177 and 178 were 

 single as regards A. Evidence for the classification given of rabbits 177 and 

 178 is shown in tables 35 and 36. 



(7) A seventh variety of gray rabbit should produce young of the varieties 

 gray, yellow, and white, but none of other colors. It should differ from variety 5 

 in being heterozygous (single) in C. Its formula would be B 2 Br 2 E(R)A 2 CI 2 U 2 Y 2 . 

 We are unable to cite an undoubted example of this variety, though it could 

 probably be produced by crossing variety 3 with variety 5, as well as in several 

 other ways. 



(8) An eighth variety bears the same relation to variety 6 that 7 does to 5. 

 It is of the formula B 2 Br 2 E(R)ACI 2 U 2 Y 2 , and it produces young of the 5 visibly 

 different classes gray, black, yellow, sooty yellow, and white. This variety 



