Three hundred and sixteen (35%) of the American-born Japanese children whose height, weight, and skeletal age were recorded in 1956-57 were reexamined as young adults between 1968 and 1974, when they were found to be taller, heavier and shorter legged than men and women in Japan who were born in the same years as they. These differences between the American-born and the native Japanese adults were relatively smaller than they had been during childhood, due to both an acceleration in the growth rate of the native Japanese and a concomitant decline in that of the American-born Japanese during the intervening years. A comparison of our 1956-57 data with Kondo and Eto's findings in Los Angeles in 1971 shows that there has been very little increase in the size of California-Japanese children since 1956. The curves of average heights of native Japanese children 6 to 20 years of age, at 10-year intervals from 1900 to 1970, disclosed the changing rate at which they grew during different decates of that period. Those curves and other data discussed in this paper provide additional evidence of the biological superiority of the human female as compared with the male.