84 STUDIES ON PATHOLOGIC OVA. 



the tissues of the cord, like those of the cyema itself, have undergone great changes. 

 Rarefaction of the mesenchyme and cavity formations are very common. Portions 

 of the allantoic stalk were frequently preserved, although sometimes in a form so 

 greatly modified as to make their recognition doubtful. 



The yolk-sac also frequently was present, though changed so very much that 

 recognition of it could not always be certain. It frequently had a greatly thick- 

 ened, fibrous wall which was fused completely with the chorion. 



The decidua was present in only 31.2 per cent of the 48 specimens in this 

 group and was infiltrated in 80 per cent of these, excluding 2 doubtful cases. This 

 infiltration was marked in 58.3 per cent and slight in 41.7 per cent of the speci- 

 mens. Abscess formation was relatively rare. The infiltration also was less 

 marked than in the preceding groups, especially in the first three, and cases sug- 

 gesting interference were rare, although several were noted. 



Hydatiform degeneration was present in 38.5 per cent, with a probable addi- 

 tional 6.3 per cent. Infiltration of the decidua was present in only 3 'or 4 of 

 these specimens, but not much reliance can be placed upon this small number. 



Since the decidua was absent in 6 of the 10 cases in which it was definitely 

 stated in the history that there was no venereal disease or evidence of it, it is 

 impossible to throw any further light on these specimens; for, as already stated, 

 infiltration does not occur in the chorionic vesicle until the latter is extremely 

 degenerate. Hence, in the absence of the decidua, one can only draw inferences 

 as to its condition from changes in structure of the chorionic vesicle. Since hydati- 

 form degeneration was present in 4 of these 6 cases, the inference that the decidua 

 of these, if present, would also have shown infiltration is justified. In 4 of the 9 

 cases in which the absence of venereal disease was reported, and in which the 

 decidua was present, the latter undoubtedly was infiltrated. This infiltration was 

 mild in 2 cases and severe in 2. In one of these instances in which it was especially 

 emphasized that the patient stated that she had never had leucorrhea, and in 

 another in which it was stated that leucorrhea was present but that the patient 

 had never had venereal disease, the infiltration was very marked. Further con- 

 firmation of the clinical diagnosis was found in three cases of lues and in one of 

 endometritis. 



In two cases of this group in which the alleged cause of the abortion was 

 respectively a blow in the abdomen and a fall, severe infection and even abscess 

 formation were present; and in a third, in which an accident was blamed, hydati- 

 form degeneration was recognized, and hence endometritis probably existed. In 

 a fourth case in which abortifacients were supposed to be responsible for the 

 termination of pregnancy, a mild endometritis and changes suggestive of lues were 

 present; and in a fifth instance, in which the abortion was attributed to quinine, 

 the specimen plainly suggested that it came from an induced abortion. The sixth 

 case, which was said to be spontaneous, had the microscopic appearance of an 

 old retained specimen. 



The structural changes noticed in the decidua, in the chorionic vesicle, and 

 in the amnion, did not differ in kind from those seen in previous groups. Calcifica- 



