. Cyclopedia of farm animals. Domestic animals; Animal products. POULTRY POULTRY 531. Fig. 527. Single-combed black fowl. The grandchild (F?) of a rose-combed Black Minorca and a single-combed White Leghorn. See Fig. 526. variety. In Figs. 526 and 527 are shown two grand- children (F2) of a rose-combed Black Minorca and a single-combed White Leghorn. Among others, a rose-combed white and a single-combed black fowl appeared, thus revers- ing the relation of comb and color. Since the heterozy- gotes contain the dom- inant character, this alone will appear in the body as in Fl7 and it will often
. Cyclopedia of farm animals. Domestic animals; Animal products. POULTRY POULTRY 531. Fig. 527. Single-combed black fowl. The grandchild (F?) of a rose-combed Black Minorca and a single-combed White Leghorn. See Fig. 526. variety. In Figs. 526 and 527 are shown two grand- children (F2) of a rose-combed Black Minorca and a single-combed White Leghorn. Among others, a rose-combed white and a single-combed black fowl appeared, thus revers- ing the relation of comb and color. Since the heterozy- gotes contain the dom- inant character, this alone will appear in the body as in Fl7 and it will often be impos- sible to distinguish be- tween a homozygous dominant and a hetero- zygote. Yet, to get a pure race one must separate them. Con- sequently, the dominants of F3 must be tested. To test a dominant, mate it with a recessive. If the dominant is pure (DD), all offspring will be of the dominant type ; if impure (DR), the offspring will be equally of the combination DR and RR, and hence half of them will be of the recessive type. Hybrids, which, on testing, throw only dominants, may be used to found a pure dominant race. Thus, one character at a time (or several at a time if great numbers be available), a race pure in respect to the desired characters, whether dominant or recessive, may be built up. And the prog- eny of members of this race, bred inter se, will ordinarily show no re- version to the eliminated characters. The new race is established but it is not yet perfected. In the process of hybridization, the various characters often become somewhat damaged. It will be necessary to improve them ; and this is done by the process of selection. Those individuals in which one or more of the characters approach most nearly to the ideal are preserved for breeding. Thus, in a few generations the ideal may be fully achieved. It may be of assistance to give here a table of some of the characters of poultry, show- ing which are dominant and which recessive. It sometimes happens tha
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