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 F 2 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 2 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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