THE VILLI IN ABORTUSES. 317 



J. Kollmann (1898) found villi 1 mm. long and well developed in a chorionic 

 vesicle of 6 mm. and stated that they might either be universally distributed or 

 merely equatorial. This writer, who limited the term ectoderm to the Langhans 

 layer, apparently referred the syncytium to a maternal origin. He also spoke 

 of nonvascular villous branches about 1 mm. thick, which played the role of 

 fastening villi, and distinguished two kinds, viz, ectodermic villi without a stroma 

 and mesodermic villi with it. In 1907 Kollmann used the term villi terminales 

 for villi which had traversed trophoblastic nodules, and villi adherentes for those 

 the terminations of which ended in or were joined to each other by the trophoblast 

 or a decidual plate. 



Paladino (1899), although studying mainly the epithelium, stated that one of 

 the vesicles, the age of which he estimated as 13 or 14 days, was covered com- 

 pletely by villi. Webster (1901), who devoted considerable attention to villi, 

 recognized the presence of floating villi and found that villi, as a rule, are much 

 more numerous and are branched by the sixth week. According to Webster, the 

 mesoblast in the youngest villi is finely granular, vacuolated, and stains but faintly. 

 He also found villi which were attached to the chorionic vesicle by syncytial 

 stalks only, an occurrence which he attributed to failure of the mesoblast to pene- 

 trate the early plasmodial bud. He found many more small villi present by 

 the fourth month, and stated that the mesenchyme around the vessels is usually 

 condensed at this time. By the sixth month the villi were said to be slender and 

 more branched, and lateral budding was said to be much less frequent. Aside from 

 changes in the epithelium, Webster found the connective tissue of the small villi 

 to be loose or mucoid as term was approached, and stated that the villi are more 

 simple, possess fewer buds and branches, and are in part nonvascular in the region 

 of the chorion lave by the sixth week. 



Marchand (1903) found that villi 1 mm. long uniformly covered a chorionic 

 vesicle 14 to 15 mm. in size, except at its mid-portion, in which a fold was located. 

 None of the villi were said to reach the capsularis at this time and all were non- 

 vascular. Marchand stated, however, that the mesenchyme cells frequently were 

 arranged in rows so as to simulate young capillaries. In a second specimen, 14 

 mm. in size, the villi, on the contrary, were largely restricted to the region of the 

 decidua basalis. Only isolated villi were found at the opposite poles, and but very 

 few on the lateral surfaces. These were branched but slightly, but some of them 

 were vascularized. 



Bonnet (1903) described early lymphatics in the villi and represented a 

 ciliated border and also a membrana limitans. It seems that Kupffer (1888) was 

 the first to describe the ciliated border, reported later also by Marchand (1903), 

 and even more recently by Friolet (1905), Stoffel (1905), Daels (1908 a ) and Herzog 

 (1909), in all thin sections of the villi. Rossi Doria (1905) explained the so-called 

 ciliated border by the manner in which the erythrocytes become embedded in the 

 margin of the syncytium; and although a reticulum also has been described in the 

 stroma of the villus, later histologic studies do not confirm the presence of it, of a 

 membrana limitans, or of a ciliated border. These things, however, do not deny 



