66 INHERITANCE IN RABBITS 



Plainly it is unprofitable to attempt to find illustrations of all these con- 

 ceivable variations. We shall content ourselves with noticing some of 

 the more important varieties of albinos and presenting evidence that each 

 of the 4 variable factors, A, E, I, and U, is transmitted through albinos. 



The following albino varieties may be expected to occur: 



(1) White producing gray only (in crosses with any pigmented variety); for- 



mula, B 2 Br 2 E 2 A 2 I 2 U 2 Y 2 . 



(2) White producing black only (in crosses with black or any pigmented variety 



recessive to black); formula, B 2 Br 2 E 2 I 2 U 2 Y 2 . 



(3) White producing yellow only (in crosses with yellow or sooty individuals) ; 



formula, B 2 Br 2 R 2 A 2 I 2 U 2 Y 2 . 



(4) White producing sooty only (in crosses with sooty); formula, B 2 Br 2 R 2 I 2 U 2 Y 2 . 



(5) White producing gray, and black (in crosses with black or any pigmented 



variety recessive to black); formula, B 2 Br 2 E 2 AI 2 U 2 Y 2 . 



(6) White producing gray, and yellow (in crosses with yellow or sooty) ; formula, 



B 2 Br 2 E(R)A 2 I 2 U 2 Y 2 . 



(7) White producing gray, black, yellow, and sooty (in crosses with sooty) ; 



formula, B 2 Br 2 E(R)AI 2 U 2 Y 2 . 



(8) White producing black, and sooty (in crosses with sooty); formula, 



B 2 Br 2 E(R)I 2 U 2 Y 2 . 



(9) White producing yellow, and sooty (in crosses with sooty); formula, 



B 2 Br 2 R 2 AI 2 U 2 Y 2 . 



Another set of 9 varieties, quite similar to these, would produce only 

 pale-pigmented offspring. As regards the intensity factor they would 

 be D 2 instead of I 2 . Another set of 9 varieties would produce both dilute 

 and intensely pigmented offspring, being heterozygous, I(D), as regards 

 the intensity factor. 



Nine other varieties, in which S 2 replaces U 2 , would produce only spotted 

 young; and another set of 9 would produce both spotted and self-colored 

 offspring; in these U(S) would replace U 2 . Another set of 9 varieties 

 would produce only pale-pigmented spotted individuals, another would 

 produce pale-pigmented individuals, both self and spotted; and lastly a 

 set of 9 varieties would produce both dilute and strongly pigmented indi- 

 viduals, both spotted and self-colored. 



It is probable that the foregoing list of 72 varieties could be duplicated 

 in varieties having the Himalayan modification, and duplicated a second 

 time in varieties heterozygous in the two sorts of albinism. 



A few examples will now be mentioned of some of the 9 varieties of 

 albinos first enumerated, or of animals differing from those 9 varieties 

 in one or two characters only. 



Variety i is represented in our c? 1425, which when mated with black 



9 1541 produced n young, all gray, and when mated with yellow 9 547 



(variety 3) produced 4 young, all gray. Variety 2, but heterozygous in 



the Himalayan modification, C', and in spotting with white, U(S), is rep- 



