Studies in Hatchability

Since the problem of securing the largest possible number of chicks in proportion to the total number of eggs incubated is of considerable economic significance, it is important to ascertain the nature of any factor that may affect hatchability adversely. The results of a number of investigations, as reported by Jull (1930), show that fertility is not inherited but that hatchability is inherited. Factors that affect hatchability may also affect other problems of economic importance or vice versa. For instance, do factors that affect the number of eggs laid during the hatching season also affect the hatchability of the eggs incubated or does the number of eggs laid during the hatching season in itself affect hatchability? In so far as the writer is aware no data have been published bearing on this point. Lamson and Card (1920), using White Leghorns, observed that the number of eggs laid during the 90 . . .