POST-MORTEM INTRAUTERINE CHANGES. 283 



tinue to grow for some time and apparently often do so, for, as is well illustrated 

 by many things, they are much more independent, not only of the fetal circulation, 

 but also of the conceptus, than the other components. Strahl and Henneberg 

 (1902) also found the ectodermic elements of the placenta in guinea-pigs more 

 resistant than the mesodermic. Some investigators (His, for example) expressed 

 the opinion that, although survival of tissues, within both the cyema and the 

 vesicles, is possible after death of the embryo, one really can not regard such 

 tissues as truly living, although cell proliferation nevertheless may be present. 

 Giacomini and His both spoke of cell proliferation, and Mall later used the term 

 dissociation as including both migration and proliferation of cells. It may be 

 recalled in this connection that Miiller (1847) also spoke of proliferation of the 

 epithelium of the villi as being common in aborted ova, and that Giacomini (1888) 

 stated that the cells of the central nervous system tend to become uniform and 

 also seem to multiply because they no longer can be accommodated in the space 

 provided for them. His, Giacomini, Grawitz, Mall, and Engel all believed that at 

 least a proliferation of "round cells" occurs and that they are wandering or migra- 

 tory in nature. Marchand (1895) also spoke of an infiltration of the conceptus by 

 leucocytes, but did not believe, as did Grawitz, that they were autochthonous in 

 origin. Although Daels (1908 b ) stated that maternal leucocytes can penetrate 

 normal syncytium in order to reach a necrotic area beyond, Nattan-Larrier and 

 Brindeau (1905 a , 1908) concluded that leucocytes never invade the stroma of the 

 villi as long as the epithelium is intact. The conclusion of the latter investigators 

 is wholly in accord with my own observations, and it would seem extremely diffi- 

 cult to determine whether leucocytes seen somewhere in the stroma of the villi or 

 of the chorionic membrane really are fetal or maternal in origin. According to 

 Windle (1893), the so-called round cells arise in the stroma of the villi, but Wallen- 

 stein believed that such an infiltration can occur only into dead or dying embryonic 

 tissue. Berlin (1907) also spoke of the presence of extensive leucocytic infiltration 

 in one of her cases, and Engel (1900) concluded that in one of the cases described 

 by him the liver was completely destroyed by proliferating round cells which he 

 apparently assumed to be phagocytic. 



Microscopic evidence for the survival and growth of the cyema or certain 

 parts thereof does not rest solely upon the transformation of various tissues and 

 organs into "round cells," however. Giacomini and Wallenstein both stated that 

 mitotic figures were observed by Chiarugi, but the latter seems to stand alone in 

 regard to this observation. But, even if confirmed, the occurrence of mitoses 

 locally would not establish the occurrence of a correlated proliferation which could 

 rightly be designated as growth. Nor could the well-known independent survival 

 or even growth of still-implanted villi or, more properly speaking, of the syn- 

 cytium and stroma, in cases of hydatiform degeneration and chorio-epitheliomata, 

 be regarded as establishing the occurrence of normal growth in the vesicles or the 

 cyemata of conceptuses. 



Post-mortem obliteration of the vessels would seem to fall more in this cate- 

 gory, but the post-mortem occurrence of this phenomenon even is as yet unproved. 



