The Acid-Base Status of the Blood of the Developing Chick Embryo

Abstract

1. The pH, carbon dioxide tension, bicarbonate and base excess levels of chick embryos have been measured during the period of 11 days of incubation until the 2nd day post hatching. 2. The carbon dioxide tension rises continuously from a value of about 20 mm. Hg on day 11 to a maximum of almost 60 mm. Hg on day 19. 3. The bicarbonate content rises rapidly from the 12th day (16 m-equiv./l.) until the 16th day (33 m-equiv./l.). 4. The pH falls to minimum values on the 13-14th day and the 19th day. 5. These variations are discussed in relation to the physiology of the developing embryo and its acid-base metabolism.