The fractions studied were yolks with yolk sacs and embryos including amnion and allantois with their contents. Ether soluble lipid P was detd. colorimetrically, lecithin gravimetrically as choline chloro-platinate, and cephalin gasometrically as amino N. Phospholipid metabolism reached its highest stage between the 15th and 17th days of incubation. Lecithin and cephalin, accounting for about 87% of the ether soluble lipid P by the methods of analyses used, parallel each other and show the same fluctuations as does ether soluble lipid P during the incubation period. They maintain a ratio of approximately 3:1 respectively in the yolk as well as the embryo fraction throughout the period studied.