64 INHERITANCE IN RABBITS 



young; expected i: i. We have had several other yellow rabbits which 

 were probably of this same variety, but they were less extensively and 

 inconclusively tested. 



Variety 2 is represented in a yellow rabbit obtained by purchase 

 (c?i256). He was mated with 9 547 yellow, variety 3, and produced 

 9 young, all yellow (as expected) ; by yellow 9 745^, variety 4, he produced 

 4 yellow and 3 white young (expected 3:1); and by black 9 1230 and 

 9 1 23 1, variety 7, he produced 8 yellow, 3 gray, and i blue-gray young; 

 expected 4: 3: i. 



Variety 3 is represented in yellow females 547, 714, and 11 15, which 

 in matings with yellow males of variety 4 produced 24 yellow and 2 sooty 

 young, but no white ones. Had these females been of variety 4 they 

 should have produced 25 per cent of white young in the mating mentioned. 

 It is possible that the recorded number of sooties is too small, owing to 

 a failure in our earUer records to discriminate sooty from yellow. No 

 such possibility exists in the case of the records for albinos. One of the 

 females already mentioned, of variety 3 (9 1115), when mated with sooty 

 J 1340 produced 2 yellow and 6 sooty yoimg. 



Another j^ellow rabbit of variety 3 was the lop cf 179 (plate 2, fig. 8). 

 When mated with the sooty "old female lop" (plate i, fig. 2) he produced 

 4 yellow and 4 sooty young (expected 1:1); and when mated with black 

 females of variety 4 (9 9 105, 167, and 247) he produced 7 gray, 5 black, 



6 yellow, and 7 sooty young (expected 1:1:1:1). Notice in the matings 

 with black females the total absence of albinos, though all these females 

 had produced albinos by other mates. 



Still another male of variety 3, c?3i9, son of the sooty old female lop 

 by gray J 176, variety 5, when mated with the black 9 247 (variety 4) 

 produced 2 gray, 2 black, 2 yellow, and i sooty young (expected i: i: i: i). 



Variety 4 is represented in our "Cutler's yellow" and in 9 745^ pro- 

 duced by black 9105 (variety 4) mated with yellow c?3i9 (variety 3). 

 When "Cutler's yellow" was mated with the above female, 745-2-, he pro- 

 duced 4 yellow, 3 sooty, and i white young (expected 9:3:4), WTien 

 mated with sooty females 632 and 647 (variety 2), he produced 7 yellow, 



7 sooty, and 2 white young (expected 3:3:2). 



SOOTY. 



Sooty rabbits differ from yellow ones only in the factor A, which they 

 lack. Theoretically 8 varieties are possible, viz: 



(i) Sooties producing sooties only, when mated inter se; formula, B2Br2R2C2l2U2Y2. 



(2) Sooties producing sooty, and white; formula, B2Br2R2Cl2U2Y2. 



(3) Sooties producing sooty, and pale sooty; formula, B2Br2R2C2l(I^)U2Y2. 



(4) Sooties producing sooty, pale sooty, and white; formula, B2Br2R2CI(D)U2Y2. 



The 4 remaining varieties would be like these, except as regards the 

 factor U, in which they would be heterozygous, U(S), instead of homozy- 



