82 STUDIES ON PATHOLOGIC OVA. 



such changes in form as there represented may be the result of maceration alone 

 will be considered in a later chapter. 



That lysis of the entire conceptus, even including cyemata belonging in this 

 group, may become complete is indicated by such a specimen as No. 2197, shown 

 in figure 29. The cyema of this specimen not only has become markedly modified 

 in external form, but upon microscopic examination is composed of nothing but a 

 web containing remnants of nuclei, the whole forming a perfectly homogeneous 

 mass. In view of this fact, the external form of this specimen really was remark- 

 ably preserved. 



An interesting specimen belonging in this group is No. 587, represented in 

 figures 30 and 31. While studying this specimen attention was attracted by the 

 small cavity in the wall of the main chorionic vesicle, which contained the cylindri- 

 cal cyema. Upon further examination it became evident that this smaller cavity 

 was surrounded by a degenerate chorionic membrane which was not a diverticulum 

 of the main vesicle, and that in fact we were dealing with a twin pregnancy similar 

 to No. 1840, to be referred to later. The larger of these two chorionic vesicles, 

 in the villi of which the smaller is contained, measures 58 by 38 by 29 mm., but 

 the smaller measured only 9 by 6.5 mm. in the fixed condition. The latter con- 

 tained no trace of the cyema at the time of examination, and the very degenerate 

 condition of the chorionic wall, and especially of the amnion, makes it decidedly 

 unlikely that the small though not necessarily rudimentary cyema which it may 

 have contained earlier in its history was lost before it came to my attention. The 

 photograph of the portion of this abortus shown in figure 31 suggests, and an 

 examination of the gross specimen confirms, the surmise that the smaller vesicle 

 was located at the point indicated by the leader in figure 30, the photograph origi- 

 nally taken of the specimen, which shows the presence of the cylindrical cyema. 

 Since a degenerate decidua still separates the villi of the respective vesicles in the 

 area of most intimate contact, it is evident that the larger vesicle must have cap- 

 tured the smaller, as it were, by surrounding it. It thus probably hastened its 

 strangulation and death, which may, however, have been fully assured by the 

 existence of an inflammatory decidua. The only content of the smaller chorionic 

 vesicle is coagulum (magma) with some faint traces of the amnion in the form of 

 coagulum. The villi of the smaller specimen are almost completely degenerate, 

 and the stroma of the villi of the larger, which is non-vascular, has undergone 

 mucoid degeneration. 



From what has been said, it is evident that we have here not an evidence of 

 superfetation but double-ovum twins, one of which survived for a considerable 

 period beyond the time of death of the other. Moreover, although both ova may 

 have begun their uterine development equally well, the smaller must soon have 

 been throttled or surrounded by the larger. Or the smaller, perchance, may have 

 become implanted in a more unfavorable portion of the decidua and therefore 

 have succumbed earlier. Since it is wholly unlikely that any portion of the cyema 

 was preserved in the smaller vesicle, this specimen becomes classified in group 3 

 or 2, accordingly as we do or do not recognize a trace of the amnion in the fine line 

 of coagulum which extends along the interior of the chorionic membrane. The 



