THE VILLI IN ABORTUSES. 321 



these villi, but it is not improbable that one of the specimens, shown in figure 244, 

 illustrates incipient hydatiform changes. 



In contrast with this specimen stands the vesicle, No. 2053, shown in figure 

 245. This is a somewhat older, but perfectly normal, chorionic vesicle, some of the 

 villi from which are shown in section in figure 246. All of the villi of this specimen 

 are of approximately the same development, and although trichotomy is present 

 and simpler forms of branching are common, no marked diminution of the parent 

 stem seems to occur at the point of branching. Moreover, the branches are approx- 

 imately as large in caliber and sometimes even larger than the main trunk. 



Somewhat older vesicles are Nos. 866, 2108, and 1892, represented in figures 

 247, 248, and 249. The first of these possesses decidedly fibrous, filiform villi, 

 partly covered by decidua, such as are not uncommon in cases of retention. No. 

 2108 shows the characteristic towsled appearance of the villi in many chorionic 

 vesicles with early hydatiform changes. The villi in these vesicles are usually 

 longer than they ordinarily should be, and this fact alone shows that the stroma 

 must have grown, unless one assumes, as did Daels (1908 a ), that it is mere y pulled 

 along by the proliferating exochorion. In view of this belief, it is especially inter- 

 esting that Daels thought that the stroma nevertheless might be increased instead 

 of rarefied. 



The villi in No. 1892 show early maceration changes, and that growth of this 

 vesicle ceased some time before abortion is indicated also by a menstrual age of 

 54 days, although the size of the vesicle suggests an age of only 42 days. Some 

 villi from this specimen, represented in figure 250, show the presence of maceration 

 and also establish the fact that the villous trees have reached considerable com- 

 plexity at this time. When maceration changes are more prolonged and lysis of 

 the villi advances so far that they are structureless or almost so, one gets such 

 shadow forms as those represented in No. 2197 (fig. 251). In these villi nothing 

 remains but a mere gossamer, and the exterior of the entire chorion often has an 

 eiderdown appearance, as suggested in a minor degree by this specimen (fig. 252) 

 and to a far greater degree by No. 993, shown in figure 259. The villi of the former 

 vesicle, the exterior of which measured 23 by 20 by 16 mm. and the interior 16 

 by 13 by 10 mm., although only 2 to 4 mm. long, nevertheless have reached con- 

 siderable complexity in form, for a dozen or more branches sometimes leave the 

 main stem at about the same place. Villi from other vesicles of approximately 

 the same age may, however, be much longer, as illustrated by No. 1287, represented 

 in figure 253, a specimen which also shows early hydatiform degeneration. In this 

 case the relatively small size of the chorionic vesicle is evident at once upon 

 inspection of the cross-section of the entire vesicle. The presence of matting 

 and maceration is equally evident, and anyone at all familiar with these vesicles 

 would not expect to find many traces of an embryo. 



The presence of hydatiform degeneration is very common in abortuses of the 

 fifth to sixth week. This is well illustrated by the villi shown in figure 255. A 

 fairly normal villus and, for a specimen of this age, the largest found, is repre- 

 sented in figure 254. Many small knobs are seen along the branches of this villous 



