HEREDITY 



A practical question of some importance is 

 how to manipulate simultaneously blending (or 

 seemingly blending) and Mendelian inheritance. 

 This must be by a system of line-breeding in 

 alternate generations, not in successive genera- 

 tions. To test the practicability of this matter 

 I several years ago set myself the task of com- 

 bining in one race the large size of some lop- 

 eared, yellow rabbits which I had, with the 

 albino character of some small white rabbits 

 of common race. A first cross produced gray 

 rabbits of intermediate size, but no white ones. 

 On inbreeding the gray animals, there were 

 obtained in Fj white young of intermediate 

 size. These were now crossed again with the 

 original yellow stock, and again colored young 

 were obtained, but now with % of the desired 

 increase in size. These bred inter se again 

 produced albinos, this time of the % size. A 

 third cross with the original large stock brought 

 the size up to % of that desired, and combined 

 it in F, with the desired albinism. Having 

 satisfied myself of the correctness of the 

 method, the experiment was now discontinued. 

 By further crosses, especially with a fresh lop- 



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