Premium
The effects of breed on the growth of the chick embryo
Author(s) -
Byerly Theodore C.
Publication year - 1930
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1050500203
Subject(s) - biology , breed , hatching , embryo , heterosis , hybrid , incubation , zoology , significant difference , andrology , genetics , botany , medicine , biochemistry
The growth of chick embryos of heavy and light breeds and the reciprocal crosses between them is described. The embryos of the heavier breed and the hybrids were found to be somewhat heavier than the embryos of the lighter breed from the tenth day of incubation to hatching time. In eggs of the same weight from the two breeds the size difference tends to disappear toward hatching time, probably due to the equivalence of the strictly limited food supply. It is pointed out that the size difference is more probably due to difference in the proportion of cells dividing at a given time than to a difference in duration of mitoses. The mortality of the hybrid embryos was intermediate between that characteristic of the parent breeds, while the percentage of monsters in the hybrids was less than that for either parent breed. There is thus some indication of heterosis.