CHANGES IN THE MATERNAL ORGANISM 493 



other hand, that the hormone is contained in the tissues of the 

 foetus.'' By its activity during pregnancy, it leads to a pro- 

 hferation of the mammary tissue, while the cessation of the 

 stimulus after parturition brings on the secretion of milk. 



According to Liepmann,^ the maternal blood contains a 

 special protein, elaborated by the placenta, which may be re- 

 cognised by the biological reaction, and Freund ^ states that 

 the precipitable substance is present in the urine of pregnant 

 women. Others have been unable to find such a substance 

 either in the blood or urine (see Weichardt and Opitz *). 



Veit's ^ theory is also sub judice. Taking up Schmorl's ° 

 discovery that emboh of placental cells may be found in organs 

 of the mother in eclampsia, he extends it to normal pregnancy, 

 and postulates that syncytial fragments and even whole vilh pass 

 regularly into the maternal circulation.- There they give rise to 

 an anti-body, a syncytiolysin, which itself dissolves the circulating 

 syncytium. He also seeks to explain, by the activity of the 

 lysin, the absorption of haemoglobin and other' proteins from 

 the intervillous space by the vilh, the pigmentation of the skin 

 and vaginal mucous membrane from superficial emboh, and the 

 phenomena of telegony from the circulation of elements derived 

 in part from the paternal side.' 



* It is conceivable that both views are right, since the main mass of the 

 placenta is as much a part of the fertilised ovum as the foetus itself. In 

 future investigations, the better recognition of the composite structure of 

 the placenta is desirable. In many animals it is possible to separate the 

 maternal and foetal tissues with considerable accuracy, and any effect ob- 

 tained from one or other part can be defluitely ascribed to the modified 

 uterine mucous membrane, or to the extra-embryonic part of the ovum. 



^ Liepmann, " Ueber ein fiir menschliche Plazenta spezifisches Serum," 

 Daut.med. Woch., 1902,' 1903. 



' Freund, "Beitrage zur Biologie der Sohwangerschaft," Vortr. auf. d. 

 76 Naturf. zu Breslau, 1904. 



* Weichardt u. Opitz, "Zur Biochemie der Sohwangerschaft," Deutsche 

 med. Woch., 1903. 



* Veit, " Ueber Deportation von Chorionzotten," 2e«7«c/w-./. Qeh.u. Gyndk., 

 vol. xliv. Also Veit u. Scholten, " Synzytiolyse und Hamolyse," Zeitachr. /. 

 Oeb. u. Gyna'c, vol. xlix., 1903. 



" Schmorl, Path.-Anat. Vnterauchungen iiher die Puerperaleldampsia, 

 Leipzig, 1893. 



' The discussion of the relationship between the deportation of chorionic 

 villi and the pathology of eclampsia, pregnancy kidney, placental polypi, 

 hyperemesis, &c., falls outside the scope of this work. 



