The total blood volume of normal newborn infants was estimated by Schückling1 in 1879. Since that time seven investigations have been made, but in only four (Lucas and Dearing2; Bakwin and Rivkin3; Robinow and Hamilton4; Brines, Gibson and Kunkel5) were infants studied during the first month of life. Results of these studies and of those of Schücking are summarized in table 1. Values for plasma volume and for total blood volume of the newborn cannot be considered to have been firmly established, for two reasons. Except in the work of Brines, Gibson and Kunkel, the most accurate method of estimating volume was not employed. Furthermore, only Schücking took into account the addition of placental blood to the circulation of the newborn infant when clamping the umbilical cord is delayed, although Robinow and Hamilton (1940) recognized this possibility and discussed it in their article.