VILLOUS NODULES. 331 



as illustrated by the teased preparation shown in figure 290. It is not uncommon 

 to find half a dozen or more nodules in section in a single field of the microscope 

 under low magnification of cross-sections of villi, and when they are so numerous 

 as this the villi in these areas may look matted in consequence. 



They never seem to attain any considerable size, seldom becoming larger 

 than 1 to 2 mm. This would seem to imply that, whatever the cause of their for- 

 mation, the process is self-limited. I have never seen a chorionic vesicle in which 

 large areas were capped or united by these proliferations, as are the early villi 

 by trophoderm, for example; but they are decidedly resistant and persist long 

 after the villi have degenerated. Nor have I ever seen them detached, for they 

 seem to retain their hold even after the villi become decidedly macerated, as illus- 

 trated in figure 292. I, too, have found them most common in relatively small 

 chorionic vesicles, and never have seen one on mature, normal villi. 



Since I used no special microchemical methods, I can add but little to what 

 is recorded in the literature regarding their structure. I do not believe, however, 

 that the syncytial inclusions are syncytial in origin, or that they are ordinarily 

 degeneration products. They seem to arise directly from the cells composing the 

 nodules. Hence, as stated elsewhere (Meyer, 1918), this conclusion, if correct, off ers 

 further confirmatory evidence of the origin of the syncytium from the Langhans 

 layer. It can easily be demonstrated that the villous syncytium is penetrated rapidly, 

 as a rule, by proliferation of the underlying Langhans layer, and all stages in this 

 process of protrusion of the cellular accumulations, through the underlying syn- 

 cytium, can be found. Since marked proliferation of the Langhans layer can occur 

 without hyperactivity on the part of the syncytium, it also is clear that the syn- 

 cytium may for this reason alone fail to take part in the formation of these nodules. 

 No matter how numerous the syncytial buds in cases of exquisite early hydatiform 

 degeneration, for example, I have never seen appearances suggesting in the slight- 

 est the origin of these nodules from syncytium. It is difficult to form an opinion 

 of their functional significance, but it does not seem improbable to me that they 

 may result from an attempt on the part of the younger branches of the villi to gain 

 contact with the decidua and so restore better nutritional conditions. 



DESCRIPTION OF PLATE. 



PLATE 24. 



Fio. 283. Cross section of intensely fibrous villi from No. 7656. (See Chapter XV.) 

 Fia. 284. Conceptus showing numerous trophoblastic nodules. (After Sdmmering.) 

 FIG. 285. Portion of chorionic vesicle showing an apical villous nodule to the right and others elsewhere. 



No. 1495a. X2.4. 



FIG. 286. Chorionic vesicle showing numerous small villous nodules. No. 2197. XI. 6. 

 FIG. 287. A villous nodule completely surrounded by stroma, except at its free surface not shown in the figure. 



No. 556. 



FIG. 288. A villous nodule near the base of a villous tree. No. 2365. X7.2. 

 FIG. 289. Villous nodules and lichen-like streamers on a villous tree. No. 2204. X7.2. 

 FIG. 290. A group of teased villi bearing numerous trophoblastic nodules. No. 2225. X4.8. 

 FIG. 291. Several villi ending in a single trophoblastic nodule. No. 308. X4.8. 

 Fio. 292. A macerated villous tree, one branch of which bears a noduleon its extremity. No. 2472. X7.2. 



