PLASMA CELLS OF HOFBAUER 329 
spindle and star-shaped.’’ These cells were said to lie mainly 
near the periphery. However, Langhans, who was interested 
mainly in other problems, did not represent them nor discuss 
their probable significance. But Kastschenko (’85) represented 
them and described them as being about 9u large, and as cor- 
responding exactly in form and size to the white blood cells 
of the same embryo. According to Kastschenko, the cytoplasm - 
is reduced in quantity after the first month, so that the nucleus 
no longer is surrounded by it. The nuclei, also, are said to 
undergo a change and to appear later as solid structures. The 
latter observation cannot fail to remind one of pycnosis and 
of one of its well-known significances. Kastschenko found 
these cells mainly near the epithelium of the villi and stated 
that they vary greatly in size, number, and occurrence in the 
same placenta. The fact that Kastschenko identified the cells 
found in the mesenchyme of the embryonic villi as leucocytes 
might seem to indicate that what he saw and described were 
other than Hofbauer cells. However, his illustrations, espe- 
cially when considered in connection with those of earlier inves- 
tigators and those of Minot, leave little doubt that all these 
investigators saw the same type of cell. Moreover, it is not 
improbable that Kastschenko was influenced in his interpre- 
tation of these cells by the origin and current use of the term 
Wanderzelle. It will be recalled that von Recklinghausen (’63) 
showed that the leucocyte preeminently belonged in this class 
of cells, but even at the time that Kastschenko was writing and 
far later, all cells which were regarded as foreign to the tissue 
in which they lay still were included in the designation Wan- 
derzelle. Reference to the literature of that period will make 
this fully evident. 
Tne presence of these cells in pathologic ‘ova’ was noticed re- 
peatedly by Mall (’08), who also designated them as wander- 
ing or migrating cells in his earlier protocols. Chaletzky (91) 
also saw and described these cells, but perhaps the best de- 
scription from an earlier date is that given by Kossman (’92), 
who also refered to the Hofbauer cells as Wanderzellen, and 
gave excellent representations of them. Indeed, from an inspec- 
