IT HAS been shown by a number of workers that egg size (Benjamin, 1920; and others; and more recently Williams et al., 1949; Wiley, 1950; and Kosin et al., 1952), age at sexual maturity (Waters, 1937; and Hays, 1951), and mature body weight (Waters, 1931; Schnetzler, 1936; and others) influence the growth of chicks. However, the effect of these three factors on growth to broiler ages has generally been studied independently. The object of the experiment herein reported was to study the relative influence of egg size, age at sexual maturity and mature body weight on growth to twelve weeks of age.EXPERIMENTAL PROCEDUREEggs from a flock mating of the Oklahoma Station strain of New Hampshires were hatched in two groups. The eggs for trial 1 were hatched daily between February 5 and 14, 1949; those for trial 2 were hatched between April 26 and 30, 1949. The eggs …