HYDATIFORM DEGENERATION IN TUBAL AND UTERINE PREGNANCY. 



however, and among these were two unusually fine ones in a rare specimen of twin 

 pregnancy in the tube donated by Dr. Cecil E. Vest, of Baltimore. Since the ques- 

 tion of superfetation has been raised also in connection with twin tubal pregnancies, 

 I hasten to add that such a phenomenon, even if it ever occurs (which seems exceed- 

 ingly doubtful) can be excluded absolutely in this case. Both chorionic vesicles 

 were approximately of the same size and lay in practically the same cross-section 

 of the tube, the surfaces of contact being flattened. 



Before proceeding with the statistical findings, I may say that the abortuses 

 in the Mall Collection regarded as pathological are grouped (1) as villi only; (2) as 

 empty or partial chorionic vesicles; (3) as chorionic vesicles containing some or all 

 of the amnion; (4) all specimens containing nodular, or (5) cylindrical embryos, 

 or (6) stunted, and (7) macerated and mummified fetuses. Any one interested in 

 this classification will find it discussed and exemplified in an article by Mall (1917). 



There were 40 tubes containing villi only, and in 14 of these hydatiform 

 degeneration probably was present. In 10 specimens its presence was undoubted, 

 but in 4 it was probable only. I realize that this margin of probability is exceedingly 

 large, but this is easily understood if it is recalled that often only a few degenerate 

 villi embedded in clot were contained in the cross-sections of many of the tubes, 

 and that only a few sections were examined, not, of course, a complete series of 

 each tube. Had the entire tubes been examined, or if more villi had been present, 

 and if those present had been better preserved, the difficulty would have been 

 almost wholly obviated. However, it is idle to set forth these things, because such 

 conditions never will obtain, and the margin of probability becomes greatly reduced 

 if it is remembered that in a large series the specimens necessarily supplement each 

 other. Moreover, the changes in the villi often are so typical that they are unmis- 

 takable, even if only a few villi are present. Besides, examination in complete 

 series undoubtedly would increase, not decrease the number found. In some of the 

 doubtful cases the existence of hydatiform degeneration became probable only 

 upon comparison with the many uterine specimens previously examined. 



The evidence offered by the 36 tubal specimens in the second group, which is 

 composed of empty chorionic vesicles or parts thereof, was very conclusive, for the 

 cut portions of most of these tubes contained considerable portions or even sections 

 of whole chorionic vesicles, sometimes quite free from clot. Some of them were 

 implanted almost perfectly in the wall of the tube, and although many of them 

 were folded extremely and collapsed more or less, small areas of several were never- 

 theless implanted undisturbed within the tube. The villi in some of these implanted 

 specimens were so characteristic and the whole picture so exquisite, that the spec- 

 imens rightly belong among the very finest instances of hydatiform degeneration 

 found anywhere so far. This is true in particular of the case of twin pregnancy 

 received from Dr. Vest. In this specimen the two chorionic vesicles, the intervillous 

 spaces of which were devoid of blood, lay in almost the same transverse diameter of 

 the tube and hence had distended the latter considerably. Both were implanted 

 quite well over the entire area of contact, which included the whole perimeter of the 

 tube. The chorionic vesicles were flattened at the region of mutual contact, which 



