PLACENTA. 641 



a considerable rise in the oxidation. For this reason LOEB believes that 

 the spermatozoa save the life of the egg by bringing membrane forming 

 substances to the egg, but also other substances, which remove or make 

 inert a harmful substance or condition complex of the unfertilized egg, 

 so that even now the increased oxidation cannot have any harmful effect. 1 



The enzymes of the sea-urchin suffer an increase in natural as well 

 as in artificial fertilization as JACOB Y 2 has shown that glycyltryptophane 

 is split after fertilization but not before. 



The placenta has recently been the subject of several investigations. 

 This tissue contains a protein which coagulates at 60-65 C. (BOTTAZZI 

 and DELFINO) whose relation to the nudeoprotein, found by others, is 

 not clear. The protein found by SAVAR contained 0.45 per cent phos- 

 phorus. The nucleic acid studied by KiKKOJi, 3 which is very similar to 

 the thymus nucleic acid, originates from this nudeoprotein. Glycogen 

 occurs regularly in the placenta, and MOSCATI believes the human pla- 

 centa contains 5 p. m. glycogen. After removal the glycogen diminishes, 

 and after 24 hours it has disappeared. According to LOCHHEAD and 

 CRAMER 4 the quantity of glycogen in the placenta is not increased by 

 food rich in carbohydrate. In the fcetus (rabbits) the above authors 

 found that the placenta is a storage organ for glycogen until the second 

 half of the gestation period, when the liver begins to functionate in this 

 direction. From this time on the quantity of glycogen in the placenta 

 diminishes. 



Enzymes of various kinds, proteolytic as well as lipolytic (mono- 

 butyrase), amylases and oxidases have been found in the placenta. 5 

 In the edges of the placenta of the bitch and of cats, an orange-colored, 

 crystalline pigment (bilirubin) and a green, amorphous pigment, whose 

 relation to biliverdin is not clear, have been found. 6 



From the cotyledons of the placenta in ruminants a white or faintly rose-colored 

 creamy fluid, the uterine milk, can be obtained by pressure. It is alkaline in 



1 A complete review of the investigations of Loeb and his collaborators, with the 

 literature can be found in Vorlesungen iiber die Dynamik der Lebenserscheinungen, 

 Leipzig, 1906, s. 239. See also liber den chemischen Charakter des Befruchtungsvor- 

 ganges, Leipzig, 1908; Zeitschr. f. physik. Chem. 70, 220 (1910), Arch. f. Entwickelungs- 

 mech., 31, 658 (1910). 



2 Bioch. Zeitschr., 26, 333 (1910). 



8 Bottazzi and DelGno, Centralbl. f. Physiol., 18, 114; Savare, Hofmeister's, Beitrage, 

 11; Kikkoji, Zeitschr. f. physiol. Chem., 53. 



4 Moscati, Zeitschr, f. physiol. Chem., 53; Lochhead and Cramer, Proc. Roy. Soc., 

 80 B. (1908). 



6 Ascoli, Centralbl. f. Physiol., 16; Raineri, Bioch. Centralbl., 4, 428; Bergell and 

 Liepmann, Munch, med. Wochenschr., 1905; Savare, Hofmeister's Beitrage, 9; Bergell 

 and Falk, Munch, med. Wochenschr., 55. 



6 See Etti, Maly's Jahresber., 2, 287, and Preyer, Die Blutkristalle, Jena, 1871. 



