278 STUDIES ON PATHOLOGIC OVA. 



Since 12.8 per cent of all abortions and 32.3 per cent of all those classed as 

 pathologic in the first 1,000 accessions in the Carnegie Collection are composed 

 of villi only, of empty chorionic vesicles, and essentially of chorion and amnion 

 alone, one might assume that all these specimens represent stages in the process 

 of intrauterine disintegration and absorption. Most of them undoubtedly do 

 belong in this category, but in many cases in which villi only are found the rest 

 of the conceptus, and in others the embryo as well, has been lost. Since 46.4 per 

 cent of all tubal specimens and 71 per cent of all those classed as pathologic are 

 composed of villi only, of empty chorionic vesicles, and of chorion and amnion 

 only, it might be assumed that digestion and absorption are more active within 

 the tube than within the uterus. Such a conclusion is not justified, however, for 

 almost all tubal specimens are isolated while young, and only exceptionally does 

 one reach the later months of pregnancy. Hence, those falling in the above- 

 named three groups of tubal specimens form a relatively larger percentage.. 



Cases of partial dissolution of the embryo are of course common, as almost 

 every one knows. As far as I can learn, however, the two cases reported here are 

 the only ones offering unequivocal proof that dissolution of the entire conceptus 

 may be absolutely complete and that the intact empty decidua then may be 

 aborted. Such an event could, for various reasons, probably occur only in the early 

 stages of pregnancy and must undoubtedly be relatively rare. Nevertheless, I 

 am convinced that careful examination of all material aborted will multiply the 

 evidence. From these things it would also seem possible that rarely pregnancy 

 might supervene and be terminated without having attracted any attention what- 

 soever. 



The phenomenon of intrauterine lysis is interesting also from a chemical 

 standpoint. What the anatomist would like to know is not merely in what respects 

 the composition of the intra-amniotic and peri-amniotic fluids has been changed, 

 but just what the enzymes are that have caused a complete lysis of the embryo, 

 where these first arise and act, and how and why they become active. These and 

 many other questions the chemist only can answer. For this answer fresh ma- 

 terial is indispensable, but this the neighboring practitioners or a closely associated 

 clinic can supply. That the lysis of these early embryos, and undoubtedly also of 

 the chorionic vesicles, is not due primarily or even very materially to phagocytic 

 activity is very evident, even upon cursory examination. In the presence of the 

 intact chorionic and amnionic vesicles in some specimens, such a process is wholly 

 excluded. Besides, one never sees any evidence of phagocytosis of the preserved 

 fetal by the maternal tissue in human conceptuses. Evidences of the contrary 

 process, however, are not wanting. 



That the embryo or fetus usually is the first member of the conceptus to dis- 

 appear has already been implied by stating that in 32 per cent of the abortuses 

 grouped as pathological in the Carnegie Collection the embryo is missing. Al- 

 though the absence of the embryo does not necessarily mean, in every case, that 

 it underwent complete autolysis, this no doubt is true in by far the great majority 

 of these cases. The fact that the embryo disappears first may be due to a lower 



