During the last few years the Iowa Child Welfare Research Station has been making a series of measurements of infants from birth to 3 years of age. When the work was first begun, small clinics were held in various towns and cities in the state to which parents brought their children for a single mental and physical measurement. In 1925, this plan was abandoned in favor of the consecutive plan of measuring at two months intervals, which affords an opportunity to study the rate at which a child is growing during a given period. The two tables herein submitted are intended as a supplement to the averages for young children presented in "Physical Traits of Young Children."1 They are based on 1,300 measurements of infant boys and 1,003 measurements of infant girls. Eight hundred and twenty-nine infant boys were measured once and 93 were measured two or more times,