PLASMA CELLS OF HOFBAUER So 
In outline they varied from irregular to circular, as stated by 
Hofbauer, and as represented by Minot (’11) in his series showing 
progressive degeneration. - Although it was easy to distinguish 
the vacuolated Hofbauer cell from the well-preserved mesen- 
chyme cell with cylindrical nucleus and many processes, speci- 
mens which represent transition forms as stated by Marchand, 
were quite common. ‘The latter generally were oval or slightly 
irregularly formed cells with a number of short processes, which 
latter, as well as the character of the nuclei and the form of the 
cell itself, certainly suggested a mesenchymal origin. They 
were also most numerous in villi the stroma of which had be- 
come vacuolated or fenestrated. Here the reciprocal numer- 
ical relationship between the Hofbauer and the mesenchyme 
cells often was especially evident. In certain areas in which 
almost no mesenchyme cells remained intact, numerous Hof- 
bauer cells occurred in all stages of degeneration. In other por- 
tions of the chorionic membrane or of the villi, mesenchyme 
cells with processes in all stages of retraction also were clearly 
outlined in the homogeneous ground substance. Such evidences 
naturally remind one of Hofbauer’s statement that “Marchand 
called his attention to the fact that these cells were mesenchyme 
cells, a conclusion which Hofbauer accepted. My implication, 
however, is not that degeneration of the mesenchyme or of 
individual mesenchyme cells can proceed only through a Hof- 
bauer stage, but that, especially in the chorionic villi, a form of 
degeneration of the mesenchyme seems to occur which gives 
rise to this peculiar cell form, the degenerate character of which 
rightly impressed Minot. This relationship also attracted the 
attention of Mall (’15), who represented degenerating villi and 
stated 
The core of the villus gradully breaks down and disintegrates. While 
this process is taking place we often see scattered through the stroma 
of the villus large protoplasmic cells. . . . . These cells. which 
I have repeatedly seen in the villi of pathological ova, may be a type 
of wandering cells; at any rate, when the villus is being invaded by 
the leucocytes and trophoblast it might be thought that they arise 
from the latter, but this is improbable. 
