Osmotic pressure and depression of freezing point of amniotic and allantoic fluids taken from the 9th, 14th, and 17th day of development were hypotonic compared with the blood serum of a chicken. In both fluids studies were made on total ash (Na, K, Ca, Mg, Cl, H2SO4, P2O5, SiO2), sugar, N, non-protein N, NH3, urea, uric acid, creatin and creatinin. Among inorganic constituents chloride is present in great quantity. The SiO2 is relatively higher in the amnistic (0.0163-0.0270%) than in the allantoic (0.0028-0.0020%) fluid. Sugar is absent. The N content is greater in the allantoic fluid. There is no uric acid, creatin or creatinin in amniotic fluid, but the allantoic fluid contains uric acid (0.01-0.02%), creatin (9th day, 0.0097%; 14th day, 0.0189%; 17th day, 0.0379%) and creatinin (9th day, 0.0203%; 14th day, 0.0230%; 17th day, 0.0561%).