GIANT-CELLS OF BONE-MARROW : 297 
illustrations of Denys: It is meonceivable, and quite without 
parallel, how a cell could continue to function phagocytically 
and continue to load itself with ingested cells to the point of 
rupture, long after its nucleus had practically disappeared through 
pressure exerted by the extraneous ingested cells. On the other 
hand, Denys’ evidence is far from conclusive that the contained 
leucocytes are actually differentiation products of the nucleated 
areas of the polykaryocyte cytoplasm. The crucial link in the 
evidence for such conclusion is lacking: he can give no satis- 
factory transition stage between the polymorphokaryocyte and 
the giant-cell ‘cysts.’ We desire a cell showing at least a score 
of isolated nuclei as a transition to the cysts containing at least 
a hundred leucocytes, interpreted as derived from nuclear buds. 
This transition stage is lacking in Denys’ series of figures. At 
most he can only show a cell with two isolated buds. Moreover, 
the intracellular leucocytes themselves appear at approximately 
definitive stages of differentiation, not at widely different stages 
of differentiation as would be expected if they actually developed 
intracellularly. 
When one considers Denys’ figures 17 to 23, one gets the im- 
pression of a mass invasion of granular polymorphs into these 
giant-cells. The nucleus is pushed to one side; it is greatly com- 
pressed and finally broken up and destroyed. The suggestion 
presents itself very persistently that these mass inclusions of 
polymorphonucleated granulocytes signify an invasion of these 
cells, due to the close juxtaposition of areas of intensely prolifer- 
ating granulocytes and less resistant areas of closely packed ad- 
jacent giant-cells. There remains no acceptable evidence that 
the hemogenie giant-cells of red bone-marrow of the rabbit pos- 
sess any intracellular leucocytopoietic function. There is, how- 
ever, a residuum of rigidly tested evidence which suggests a 
slight erythrocytopoietic capacity on the part of these cells, 
both in the yolk-sac (10) and in the red bone-marrow (12). 
