292 H. E. JORDAN 
endogenous blood-cells illustrated in Denys’ figures, however, 
only two or three have the nuclear characteristics of an erythro- 
cyte. The practically exclusive type of endogenous cell is the 
polymorphonucleated granular leucocyte, presumably the special 
granulocyte with fine eosinophilic granules. These cells fill the 
giant-cell cytoplasm, meanwhile compressing, consuming, and 
eventually destroying the giant-cell nucleus, until the original 
cell becomes a mere cyst filled with the endogenous leucocytes. 
Eventually the cyst is said to rupture and to free the new-formed 
eosinophilic granulocytes. In a section of one such cyst eighty 
cells can be counted; the complete cyst may well have included 
several hundred leucocytes. Denys concludes that this series of 
events signifies a normal hemogenic function on the part of these 
giant-cells, involving a genuine amitotic division. Heidenhain 
would interpret these phenomena as the result of the invasion 
of the giant-cell cytoplasm by phagocytic leucocytes; Dickson as 
signifying phagocytosis of polymorphs on the part of the giant 
cells. Denys’ conclusion will be further discussed below. 
Description 
This chapter will only include a description of those cells in 
my preparations which relate to the process which Denys de- 
scribes as division by ‘stenose,’ a process interpreted as leading 
to the formation of intracellular leucocytes. In figure +1 is illus- 
trated a cell which represents the beginning of the giant-cell 
series. It is essentially an enlarged hemoblast. It traces back 
to the typical hemoblast of hemopoietic tissues; and forward, by 
small gradations, to a cell like that illustrated in figure 2. The 
latter cell is much larger and contains a reniform or more deeply 
crescentic, frequently intensely staining nucleus. These two cells 
are genuine megakaryocytes. The nucleus of cell figure 2 is 
simply a modification of the spheroidal nucleus of cell figure 1. 
It seems desirable to emphasize the point that these cells were 
studied in serial sections. It is obvious that similar appearances 
would result from possible sections through very different and 
much larger nuclei, as, for example, sections of cells figures 3 
