302 



Records of Hybrid RahbiU 



then havc 13.'5 young, the descendants of the mating of black parents, who in the 

 Mendelian seuse are kuowu to have albiiiism recessive. 



Of these 133 young 28 only were albinos. 25 7o should bave been if Mendel's 

 law is coriect, for the product of DR x DR should he D + 2DR + R. Or in 

 other words, three-fourths should appear with the dominant coluur, in twu-lhirds 

 of which the white is recessive but not manifest. 



^= 21-05 7., instead of 257^. 

 Results of Black crossed with White or vice versa are sbowu iu Table II. 



TABLE IL 

 Black X White. 



3/4 ir, 1/4 5. 



t 4/5 TF, 1/5 5. 



I Spotted. 



Rabbit (51), su.spected of being a pure dominant in the li x B niatings, occurs 

 here once, therefore her litter, as well as the four from (124') may be taken out, 

 since we cannot be sure that these, as parents, coutained any white recessive. 



If these seven young are taken ont of the consideration it will be sceu that 

 27 B ; 25 W ; 3 G, and 7 spotted were born from DR x R. 



The product of DR x R according to Mendel should give equal numbcrs of 

 Da and iJs (conf. Bateson (2) p. 158). The tigures are 25 albinos in 62 or 4037o 

 instead of 50 7o' Here as before the error is on the side of too little white iu 

 the oftspring. 



In most of these the back ancestry was black. A characteristic pedigree 

 Ixxiv is shüwn below, where it will be seen that one white in every two, which 



