PLASMA CELLS OF HOFBAUER bel 
to Ulesco-Stranganowa, then, the Hofbauer and Langhans cells 
are identical. Mall (’15) also called attention to this possibil- 
ity, for, when speaking of the invasion of the mesoderm of the 
villi by trophoblast, he called attention to the presence of numer- 
ous Hofbauer cells, and added: ‘‘It would seem possible that 
these Hofbauer cells are free trophoblast cells within the meso- 
derm of the villus, an opinion already expressed in my paper 
on monsters.’’ Neumann (’97) also noticed these cells and 
referred to Virchow’s opinion regarding them, and von Lenhos- 
sek (’02) is credited in 1904 by the reviewer of his paper with 
having examined a large series of young human embryos, and 
having suggested that what Kastschenko regarded as Wander- 
zellen 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 the villi of the chorionic vesicles of which 
contained these cells. Strangely enough, Kworostansky (’03) 
also recorded the presence of these cells, and after describing 
the stroma of the villi wrote: 
Zwischen den genannten Bindegwebszellen giebt es in der wolki- 
gen Grundsubstanz Liicken, und am Rande oder im Winkel derselben 
sitzen frele andere Bindegewebszellen, die sehr gross sind, lappige, 
runde Form, wabenartiges Protoplasma und gleiche Kerne wie andere 
Bindegewebszellen haben; ihre Kerne werden auch, hie und da stern- 
formig getheilt. Da sie stets nur in Gewebsliicken gefunden werden, 
so glaube ich, sie als Lymphgefassendothelien, oder vielleicht als Lymph- 
ocyten bezeichnen zu diirfen. Man findet sie in spaiteren Stadien 
der Placenta nur sind dann natiirlich die zellen nicht mehr gross. 
The illustration which accompanies Kworostansky’s article, 
as well as his description, leaves no doubt that the cells seen by 
him are the same as those which we are considering, although 
his surmise that they are lymphocytes and that they arise from 
the endothelium of the lymphatics may, upon first thought, 
seem rather irreconcilable with such an interpretation. 
From these references alone it is evident that Minot’s state- 
ment, that the so-called Hofbauer cells were repeatedly men- 
tioned in the earlier literature, is well founded. Muggia (’15) 
states that these cells were described also by Guicciardi (99), 
