LYSIS AND RESORPTION OF CONCEPTUSES. 271 



prepartum changes must be expected in practically all other specimens which 

 form the great majority of all abortuses. 



Among the large series of over 2,000 abortuses in the Carnegie Collection, I 

 have so far found only a few specimens of almost complete intrauterine absorption. 

 In one of these, No. 698, only a few vestiges of syncytium and trophoblast remain. 

 Not a single fragment of the chorionic or amnionic vesicle or of the embryo could 

 be found upon microscopic examination. Were it not for the presence of decidua 

 and the above microscopic remnants, one might doubt whether pregnancy really 

 had supervened in this case. However, since the specimen shown in figure 8 

 (plate I, Chapter IV) was aborted with the entire intact decidua which still sur- 

 rounded the remnants of the conceptus completely, as shown in figure 169 (plate 

 16, Chap. XI), there manifestly could have been no loss of embryonic tissue either 

 before or during abortion. This abortus, which measured 50 by 20 by 13 mm., was 

 donated by Dr. N. E. B. Iglehart, of Baltimore. It had a menstrual age of 56 

 days, but the condition of the few remnants and the size of the implantation cavity 

 show that development did not proceed very far before growth was inhibited. 

 Aside from the absorption of almost the entire conceptus, the decidua not only is 

 infiltrated, but also shows degenerative changes. As illustrated by figure 169, 

 which shows the intact capsularis separated by a narrow space from the parietalis, 

 the former is filled completely by blood-clot. It is at the periphery of this clot 

 that the isolated microscopic remnants of the syncytium and trophoblast, together 

 with a few gossamer or shadow villi, are found. Since there is no blood between 

 the capsularis and the parietalis, it would seem to follow that the hemorrhage was 

 limited entirely by the capsularis, a conclusion which is indicated also by the 

 absence of a history of bleeding. Since the last menstruation began on April 11 

 and the abortion occurred on June 6, it is seen that the latter occurred on the first 

 day of the beginning of the second lapsed menstrual period. Although the appear- 

 ance and the condition of the decidua seem to suggest that considerable regeneration 

 of the endometrium had occurred, it is possible, though unlikely, that the bleeding 

 accompanying the abortion was menstrual and that hence the abortion should be 

 regarded as a mere incident accompanying the return of normal menstruation 

 rather than as the predominating event. 



That considerable restoration of the endometrium may occur while the con- 

 ceptus still is within the uterus was shown by the case of Orloff (1895). In this 

 case the endometrium was composed of a cylindrical epithelium and the uterine 

 musculature showed no evidences of the presence of gestation changes. Iwanoff 

 (1898) also found the decidua absent in a case of long retention and its place taken 

 by a low cylindrical epithelium, although the placenta was still partly attached to 

 the uterus. E. Fraenkel (1903) also emphasized the fact that regeneration of the 

 endometrium may begin before abortion occurs, and these things make it possible 

 that hemorrhage, which may occur at time of abortion, may largely be true men- 

 strual hemorrhage. . 



The absence of blood between the capsularis and the parietalis and the absence 

 of a history of bleeding do not imply that the development of this conceptus 



