310 STUDIES ON PATHOLOGIC OVA. 



degenerate erythroblast, as Minot concluded. However, in rare instances I have 

 seen a chorionic vesicle in which the rather small, clear, isolated Hofbauer cells 

 scattered throughout the stroma of a villus undoubtedly were erythroblastic in 

 origin. In these villi capillaries in various stages of disintegration were present, 

 and the erythroblasts could be traced directly to these degenerate capillaries. 

 In the earlier stages of this degeneration these degenerating erythroblasts are not 

 surrounded by spaces, however, and this is true also of early stages in the degen- 

 eration of the fixed or already detached mesenchyme cell, which later forms the 

 typical degenerating wandering cell. However, it represents but one stage in this 

 degeneration. 



It is significant that, although Hofbauer suggested that these cells might have 

 a digestive or assimilative function, he, too, frequently found fragmentation of the 

 nuclei and complete disappearance of the cytoplasm and even of the cell itself. 

 All stages of degeneration, as manifested by crenation of both cytoplasm and nu- 

 cleus, even to complete disappearance of the cell, can easily be found. Signet-ring 

 forms are common, and the nuclei are found in all stages of extrusion and 

 degeneration. The cell boundaries are often ragged, the nuclei crenated and 

 pycnotic, the cytoplasm granular, vacuolated, webbed, or fenestrated, until finally 

 nothing but a faint ring or shadow form without a trace of a nucleus remains. 

 However, in these transparent or shadow forms the nuclei, if not previously ex- 

 truded or dissolved, are frequently represented by a mere outline or only by a 

 faint trace of one. Since all stages between the latter and the well-preserved cells, 

 without vacuoles and with well-preserved nuclei and cytoplasm, and also with 

 processes, occur in well-preserved material, one can scarcely doubt their origin. 



Undoubted instances of mitoses were never seen in any Hofbauer cells, no 

 matter how well preserved. This no doubt can be accounted for by the fact that 

 from the time the mesenchyme cells retract their processes and become isolated 

 in the villus, they are in a stage of degeneration. Under such circumstances one 

 would hardly expect to see instances of cell division, although it possibly may be 

 simulated by necrobiotic phenomena. 



Hofbauer (1905), as also in his first publication, stated that the cells described 

 by him increase by mitoses which are frequent. He also found examples of what 

 seemed to be instances of pluripolar mitoses, and also noted fragmentation of the 

 nuclei. Acconci (1914 b ) also found mitotic figures in cells designated lipoid inter- 

 stitial cells by him, but most investigators say nothing about this. On the 

 contrary, a number of them specifically state that they could not find an actual 

 increase in the number of nuclei present in the stroma of villi containing large 

 numbers of these cells. Furthermore, every one except Muggia (and he also in 

 his description and illustrations, as also Acconci) has noted characteristics and 

 described the cells in such a way as to suggest the presence of degeneration changes. 

 When at all distinct, the cells are of various shapes and sizes and are surrounded by 

 a relatively large clear zone. Their occurrence is erratic, they contain lipoid granules 

 or vacuoles, and have nuclei varying considerably in size, position, and staining 

 reaction, as does also the cytoplasm. They are most frequent in degenerate villi 



