HOFBAUER CELLS. 303 



enthalten einen oder mehrere grosse blasenartige Ilohlraume, von clencn ich leider nicht 

 sicher sagen kann, ob sie Fett fiihrten, da sie mir erst nach Behandlung des Praparats 

 mit Xylol auffielen. Der Kern dieser Zellen enthielt stets Nucleoli. Die Zellen sind 

 also jedenfalls nicht in- lebhafter Vermehrung; wahrscheinlich sind es Wanderzellen, und 

 da sie auf einem wenig alteren Stadium wieder fehlen, mag ihr Vorkommen in einigem 

 Zusammenhange mit der um diese Zeit beginnenden Vascularisation des Stroma's 

 stehen." 



Merttens (1894) found the same cells in abortuses, and, in describing the 

 stroma of the villi of his first case, said : 



"An den Ernahrungszotten ist es kernreich, vielfach aufgelockert, mit stern- und 

 spindelformigen Zellen, in den Maschen jene oben fur die normalen ersten Stadien 

 beschriebenen grossen, runden oder polyedrischen Zellen mit kornigem oder auch 

 vacuolarem Protoplasma mit grossem, blaschenformigem, rundem Kern." 



Merttens seems also to have suggested that these cells are swollen stroma 

 cells, but since he made this observation somewhat disconnectedly I am not quite 

 certain of his meaning; yet the mere suggestion is particularly interesting, in view 

 of Minot's special emphasis upon the degenerate character of the Hofbauer cells. 

 Marchand (1898) also wrote: 



"Die durchsichtigen hellen Zellen im Stroma normaler oder pathologischer Zotten 

 sind mir wohlbekannt, sie konnen denen der Zellschicht sehr ahnlich sein; ich halte sie 

 jedoch fur gequollene, rundlich gewordene Bindegewebszellen, da man Ubergange zu 

 solchen findet, ebenso wie in andern Schleimgeweben." 



Ulesco-Stranganowa (1896), who also saw these cells, says that if one com- 

 pares the Langhans cells with round nuclei with these cells scattered about the 

 stroma of the villi, and which have been named "Wanderzellen" by Kastschenko, 

 one becomes convinced of the identity of these two types of cells. According to 

 Ulesco-Stranganowa, then, the Hofbauer and Langhans cells are identical. Mall 

 (1915) also called attention to this possibility, for, when speaking of the invasion 

 of the mesoderm of the villi by trophoblast, he called attention to the presence 

 of numerous Hofbauer cells, and added: "It would seem possible that these Hof- 

 bauer cells are free trophoblast cells within the mesoderm of the villus, an opinion 

 already expressed in my paper on monsters." Neumann (1897) also noticed these 

 cells and referred to Virchow's opinion regarding them, and von Lenhossek (1902) 

 is credited by the reviewer of his paper in 1904 with having examined a large series 

 of young human embryos, and having suggested that what Kastschenko regarded 

 as "Wanderzellen" were mesenchyme cells. It should be noted, however, that 

 von Lenhossek apparently came to this conclusion largely because of the absence of 

 blood-forming organs or lymphatic centers in embryos, in the villi of the chorionic 

 vesicles of which he found these cells. Strangely enough, Kworostansky (1903) 

 also recorded the presence of these cells, and after describing the stroma of the 

 villi wrote: 



"Zwischen den genannten Bindegewebszellen giebt es in der wolkigen Grundsubstanz 

 Liicken, und am Rande oder im Winkel derselben sitzen freie andere Bindegewebs- 

 zellen, die sehr gross sind, lappige, runde Form, wabenartiges Protoplasma und gleiche 

 Kerne wie andere Bindegewebszellen haben; ihre Kerne werden auch, hie und da stern- 



