VILLOUS NODULES. 329 



Pfannenstiel (1903) thought that the villous nodules are composed partly of 

 decidua, but Rossi-Doria (1905) frankly stated that they are nothing but prolifera- 

 tions of the Langhans layer, especially common on the tips of the villi. Rossi- 

 Doria nevertheless believed that the syncytium also may take part in their forma- 

 tion through proliferation by amitosis. This investigator, who made a careful 

 examination of a conceptus 9 by 8 mm., stated that the trophoblastic nodules which 

 form on the ends of the branches of the villi begin to appear after the second week 

 of pregnancy. He concluded that they form not only on the free, but also on the 

 fastening villi (Haftzotten), and doubted whether syncytium really can invade 

 these nodules, as held by some investigators. J. Kollman (1907) also reported 

 them in a conceptus 8 weeks old, and showed villi joining after passing through the 

 nodules, forming what he called "villi adherentes." 



If these nodules, found in such number on villi of many abortuses, and repre- 

 sented so well in the conceptus from Sommering, shown in figure 284, are decidual 

 in origin, then it is clear that their substance is in fact preformed, and if they 

 antedate the formation of the villi it would seem that they might appear very soon 

 after the formation of the latter. If, on the other hand, they are products of the 

 epithelium of the villi, then a short interval after the formation of the latter is 

 necessary to enable such accumulations to form. No one has held that they are 

 direct products of the ovular ectoderm, which secondarily become related to the 

 villi, and, from what has been described in the earliest known implantation stages, 

 it would seem that this is not the case. Although the ectoderm of the implanting 

 ovum apparently is extremely active, probably especially so during the invasive 

 stage of the implantation, these nodules apparently do not arise directly from it. 



In the description of some of the cases, and also in publications, I have some- 

 times used the term trophoblastic nodule. The cells composing these nodules, 

 however, undoubtedly arise from the Langhans layer, the syncytium usually 

 being absent; and since the nodules really are not remnants of the early tropho- 

 blast, it would perhaps be better to relinquish this term altogether and to refer 

 to them merely as villous nodules. However, I have been greatly puzzled to find 

 a good name for these special masses of cells arising from the Langhans layer. 

 The term insular nodule, introduced by Langhans, would be entirely acceptable 

 did it not carry with it the possibility of confusion with decidual islands, for 

 if they really were islands, confusion would be particularly likely, because 

 Langhans thought that they were maternal in origin. The term cell-nodule (Zell- 

 knoten), introduced by Kastschenko, also is not without objection for the same 

 reason. The designation "appendici durate" used by Crosti does not recommend 

 itself either, because one scarcely can speak of most of them as appendages, for the 

 simple reason that they are almost wholly embedded in the stroma of the villi. 

 Then, too, they are so small that one scarcely feels justified in speaking of them 

 as hard. In very young villi the designation trophoblastic or trophodermic nodules 

 would seem quite appropriate, especially since they frequently contain syncytial 

 masses among the Langhans cells; but later on, long after the trophoderm or tro- 

 phoblast has ceased to exist as such, this designation seems far less appropriate. 



