SUMMARY. 107 



tion and hydatiform degeneration just referred to, but such is not necessarily the 

 case. It is accounted for, in a large measure, by the greater frequency of very 

 poorly preserved deciduae, which often make the determination of infiltration ex- 

 ceedingly difficult. The tubes, on the other hand, always are sufficiently well 

 preserved, even if not perfectly so, to make a decision in this matter comparatively 

 easy. 



Although the series of cases showing hydatiform degeneration is unprece- 

 dentedly large, only 315 uterine and 104 tubal specimens were included in this 

 study. This, of course, is too small a series for statistical purposes, but the rela- 

 tively small size of these groups is compensated for to a remarkable degree by the 

 very striking parallelism existing between them. This parallelism was found to 

 exist not only between the incidence of hydatiform degeneration and of infiltration 

 in the first few groups of the tubal and uterine specimens, but also between these 

 two, and seems to indicate an extremely close relationship between infiltration and 

 hydatiform degeneration. It is not unlikely, however, that it is not so much the 

 presence of an infection itself as the changes induced by it, especially in the decidua, 

 which may be the real cause for the advent of hydatiform degeneration. 



DESCRIPTION OF SPECIMENS. 



Readers will notice direct contradictions between the first and last portions of 

 some of the following descriptions. This is due to the fact that the first portion 

 of the description is based upon the gross appearance alone and the second upon 

 histologic examination in addition. Things taken for embryonic rudiments were 

 not always found to be such. Moreover, since Mall wrote the original protocols 

 at widely different periods, some of the descriptive terms, among which are fibrous, 

 hyaline, and mucoid, are not always used in exactly the same sense. With chang- 

 ing conceptions old terms also took on a new meaning. In the earlier protocols 

 the term dissociation is used largely, if not wholly, in the sense of disintegration, 

 but later it takes on the further idea of an uncorrelated or helter-skelter growth. 

 Hence, in the earlier protocols a nodular embryo is said to be completely disso- 

 ciated when it shows practically no differentiation whatever, having a homo- 

 geneous structure. The boundaries of any organs which may have been there 

 have become effaced so completely that the individual organs can no longer be 

 recognized. 



The chief items in each protocol have been numbered for the sake of con- 

 venience. The figures mark (1) the name and address of the physician who was 

 the donor, (2A) the dimensions of the abortus or chorionic vesicle, (2B) the length 

 of the embryo or fetus, (3) the relevant clinical data, (4) notes on the gross speci- 

 men, (5) notes from the microscopical examination of a portion of the specimen, 

 and (6) comments or some significant facts bearing upon the abortus. In some 

 instances the dimensions of the abortus also represent those of the chorionic vesi- 

 cle, both with free and matted villi. It was not the purpose to make a final diag- 

 nosis, but merely to call attention to facts which might throw an interesting 

 sidelight upon the condition of the conceptus. 



