Phosphagen and Creatine in Frog’s Eggs

Abstract
1. Evidence is given that the labile phosphorus of the frog's egg is identical with phosphocreatine. 2. The sum of creatine and creatinine in the egg has been determined and identified by the measurements of the rate of colour development in Jaffé's reaction. About one-third of this amount is bound as phosphagen and about 5 per cent is in the form of creatinine.