GIANT-CELLS OF BONE-MARROW 303 
of degeneration of these ‘giant cells. These several modes are 
illustrated by the series of figures 1 to 6; 1, 2, 3, 8, 10, 11, 12, 
14, and 15; 1, 2, 3, 4, 16, 17 (23), 18 (24) and 19, and 1, 2, 3, 20, 
21, and 22. The first two series lead to terminal conditions 
where chromatin masses resembling chromosomes dissolve 
within disintegrating remnants of cytoplasm. The last two 
lead to naked nuclei, which ultimately disintegrate. The fate 
of the giant-cell seems to be to suffer a gradual diminution of its 
cytoplasm, which progressive condition imposes degenerative 
changes upon its nucleus. The function of the giant-cell seems, 
paradoxically, to be to disintegrate. This cell represents essen- 
tially an overgrown hemoblast. It may become multinucleated 
by direct division of its secondarily lobulated nucleus. In this 
phase it may occasionally differentiate erythroblasts intracel- 
lularly. There is no satisfactory evidence in the data pertaining 
to the red marrow that either the polymorphokaryocyte or the 
polykaryocyte can divide either mitotically or amitotically. 
New giant-cells arise only by differentiation from hemoblasts, 
not by proliferation of preéxisting giant-cells. 
Before proceeding to an analysis and interpretation of the 
various stages described by previous investigators as steps in 
mitotic division, it may be stated again that there is no difficulty 
in finding examples of all the various stages figured by these 
workers, notably Denys, Heidenhain, Arnold, and Dickson. 
The point at issue is not regarding the occurrence of these par- 
ticular cells, but regarding their correct interpretation. Stages 
like those illustrated in figures 5, 10, 11, and 17 occur relatively 
less frequently than the other stages illustrated. In the illus- 
trations I have attempted to give types of cells. Every cell 
shown in the works of the above-mentioned investigators can 
be referred to some one of my figures as a type, of which these 
cells may be interpreted as variations. Thus Denys’ figures 
25 to 29 are variations of my figures 12, 18, 23, and 24; his fig- 
ures 44 to 51 of my figure 5; his figures 34 to 45 of my figure 
15, ete. 
Previous workers have been impressed with such conspicuous 
structures like those of figures 5,12, 14, and 15, simulating pro- 
