| 摘要 |
Egg laying hens, of the type ABCD, are produced as offspring from cocks of the type AB and hens of the type CD. The cocks have been produced by retaining the offspring from breeding the males of lines A or B, with the hens of the opposite lines, B or A, which have retained the clear colouring of the down on the tibiotarsus of the male chicks of type AB, and the darker colouring of the tibiotarsus down on the female chicks of type AB. The hens for the breeding, of type CD have been obtained by breeding the cocks of type C with the hens of type D. The cocks of type C have been tested for their aptitude to have chicks with a tendency to rapid development of the feathers and the hens of type D have been tested for their aptitude to have chicks with a tendency to slow development of their feathers.
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