Transmitting Ability in Males of Genes for Egg Size

RESEARCH workers generally agree that egg weight depends largely upon inherited factors and there is general agreement that it depends upon several Mendelian factors. There is, however, a considerable disagreement regarding the mode of inheritance. Benjamin (1920), Hurst (1921), Kopec (1924), and Hays (1929 and 1937) all consider small egg size as dominant to large. Waters and Weldin (1929) are inclined to believe that large egg size is dominant. Evidence is meager regarding possible sex-linked genes affecting egg size probably because there is no accurate way of determining the male’s phenotype. Recently Waters (1939) has presented extensive data to indicate that the selection of dams on the basis of egg weight phenotype is far more effective than the selection of sires on the basis of their sisters’ egg weight. Unfortunately, a parallel study was not reported on the breeding ability of dams selected on the basis of their sisters’ egg . . .