,518 THE PHYSIOLOGY OF REPRODUCTION 







reaction for the diagnosis of pregiumcy." His claims, which he 

 extended to various pathological conditions of other organs, were 

 at first widely and somewhat uncritically accepted and gave rise to 

 an extensive literature. They have, however, not stood the tast of 

 experimental criticism * and his views are no longer accepted. 



From time to time evidence of ha-mopoiesis in the placenta has 

 been brought forward. Mention of it was first made by Mascjuelin 

 and Swaen 2 in the rabbit, and later by Frommel :{ in the mouse and 

 bat. Hubrecht 4 strongly upholds the occurrence of blood formation 

 in the placenta* of Tcirxius and Tupaia. The new erythrocytes arise 

 as products of the fragmentation of nuclei of the trophoblast in 

 Tarisiiis (see p. 440), and of the trophoblast, and probably also 

 trophospongia, in Tnj>aia (see p. 485). They are later set free by 

 solution of the surrounding protoplasm. Such a process is beneficial 

 both to mother and embryo. The erythrocytes are increased at the 

 expense of the ovum, and they in turn increase the supply of oxygen 

 to the foetus. 



II. CHANGES IN THE METABOLISM OF THE MOTH HI; 

 PRECNANCV 



General Consideration -s 



How does the maternal organism react to the presence of a 

 rapidly growing mass of tissue, namely the fo3tus and adnexa <*. 

 An idea of the food and energy requirements which the presence 

 of the fcietus imposes upon the maternal organism can be formed 

 from the following data. The table is a very condensed summary 

 of the figures calculated or obtained by Hotfstrom :> in his investi- 

 gation on the human subject, a prhnigravida living on an unrestricted 

 diet. The figures give the total amounts in grammes of nitrogen, 



1 Bullock, "A Critical Study of the Basis of Abderhalden's Serum Reaction," 

 The Lancet, i., p. 223, 1915. Van Slyke and others, "The Abderhalden 

 Reaction," Jon,-. lilol. <'/t<>,,i., vol. xxiii., 1915. Falls and Walker, "The 

 Influence of Pregnancy on the Proteolytic Activity of Blood-Serum," ///</., 

 vol. xxxii., 1917. Hulton, "The Formation of Specific Proteoelastic Enzymes 

 in Response to Introduction of Placenta," ibid., vol. xxv., 1916. Jobling, 

 Eggstein, and Petersen, "Serum Proteases and the Mechanism of the Abder- 

 halden Reaction," Jour. /;.>/,. M,-,!., vol. xxi., 1915. 



2 Masquelin and Swaen, " Developpement du placenta maternel chez le 

 lapin," Butt, tie I' 1 A cad. Itot/. d'- Helgique, 1879. 



3 Frommel, Ueber die Entwtcttimg <//'/ I'lui-c.ntu ro,> Mi/ntiix //<>//?'///'.-, 

 Wiesbaden, 1888. 



4 Placental haemopoiesis is denied by many authorities, including Dnval, 

 Maximow, Nasius, and Nolf. For a complete review of the subject, see 

 Hubrecht, "Ueber die Entwicklung der Placenta von Tarsius und 7V/x/y>, 

 nebst Bemerkungen iiber deren Bedeutung als haematopoietische Organe," 

 Intt-rnat. Coiiyr. of Zool., Cambridge, 1898. 



" Hoffstri'nn, "P^in Stoffwechseluntersuchung wahrend der Schwangerschaft," 

 lin. A r />./. /'/,//.</</., vol. xxiii., 1910. 



