On Phosphorus Metabolism in Embryonic Life

Abstract

1. Estimations have been made of the content of creatine phosphate and inorganic phosphorus in the chick embryo from the 70th to the 360th hour of incubation. 2. The inorganic phosphorus in per cent. of the body weight rises gradually until the 240th hour, at which time there is a sudden and enormous increase, due to ossification of bone. 3. Creatine phosphate was found to be present at the earliest stage investigated. In per cent. of the body weight it rises up to the 4th day and then slowly falls off. At the 4th day there is also a maximum in the phosphagen considered as per cent. of the inorganic plus labile phosphorus. 4. The significance of these results, especially in connection with the existing data on the appearance of muscular movements, is discussed in the text.