HYDATIFORM DEGENERATION IN TUBAL AND UTERINE PREGNANCY. 355 



more fully by Meyer (1919). No matter what the condition of the epithelium, or 

 more specifically that of the Langhans layer, the syncytium and trophoblast may 

 be, the above-noted changes in the stroma always are quite typical. They are not 

 the only changes noted, however, and their advent may differ somewhat. 



Not infrequently, changes quite comparable to those in the villi occur also in 

 the stroma of the chorionic membrane itself, a fact which has not heretofore 

 been emphasized. Also, it is frequently decidedly glassy; liquefaction may occur 

 here and there and may become complete in the course of time. Hofbauer cells 

 not uncommonly also are present. Among the changes noted in this membrane 

 the disappearance of the vessels is most common and constant, although epithelial 

 proliferation is not rare, as already stated. Moreover, when (as in one of Storch's 

 cases) a hydatiform villus is 15 cm. long, one scarcely can doubt that the stroma 

 also must have proliferated not merely degenerated. Some of the strings of 

 hydatid cysts in a specimen in the Mall Collection have a length of over 10 to 12 

 cm., and in these cases also one can hardly assume that this increased length in 

 the villi was unaccompanied by proliferation of the stroma. From these things alone 

 it follows that the stroma can not remain passive always, although Gromadzki 

 (1913) concluded that the stroma never proliferates. Vecchi (1906), however, 

 reported an increase in the stroma of the villi, and it will be recalled that Marchand 

 also implied the presence of proliferative changes in the connective tissue when he 

 wrote that they depend on those in the epithelium. 



I have never been able to find mitotic figures, a fact which may be accounted 

 for, however, by the presence of degenerative changes due to intrauterine separa- 

 tion and retention of most specimens. Indeed, the failure to find mitoses speaks 

 against proliferation in the stroma no more than in case of the epithelium, in which 

 the presence of karyokinetic figures has been reported by a few investigators only. 

 Yet pronounced proliferation of the epithelium often is present. The failure to 

 find mitotic figures is very likely due to the condition of the material. 



Careful scrutiny of a large series of specimens has revealed the fact that the 

 disappearance of the vessels in the villi, in the chorionic membrane, and also in the 

 umbilical cord is centripetal as a rule. However, in many specimens the vessels 

 not only may be present in the chorionic membrane although absent in the villi, 

 but may be very numerous and even engorged with blood. It is difficult to say to 

 what extent the engorged condition of these vessels and of those in the body of the 

 abnormal embryos sometimes contained in these hydatiform moles is due to the 

 propulsion of the embryonic blood before the advancing vascular constriction and 

 degeneration, but I am inclined to believe that the centripetal movement of the 

 process is not a negligible factor. 



Although only a few instances of the birth of a living fetus or of a fetus which 

 had reached the later months of pregnancy are recorded in the literature, it now 

 is quite generally recognized that the fetus, though dead and too small for its 

 menstrual age, usually is present. This stands in contradiction to the earlier belief 

 illustrated by the statement of Gierse (1847), that the fetus usually was reported as 

 absent, and that when present (as in the cases of Meckel, Gregorini, Otto, Cruveilhier, 



