GIANT-CELLS OF BONE-MARROW 301 
entire length, the red nucleolar staining having now disappeared 
(spireme or prophase) (fig. 10). This thread or spireme, when the 
condensation of the chromatin is complete (fig. 12), breaks up (meta- 
phase) into short segments resembling chromosomes (fig. 14), which 
become rearranged into a dense rounded globe in the center of the 
cell (anaphase) (fig. 15), after which it is probable that the resulting 
basket nucleus is rebuilt upon a more complex plan, by a process 
resembling that by which the original underwent the transformation 
into chromosomes, i.e., by stages similar to those just described, but 
occurring in the reverse order. . . . This intricate process of 
nuclear rearrangement rather than diviston is not accompanied or fol- 
lowed by corresponding division of the cell-body or telophase, the pro- 
toplasm simply increasing in bulk as the nucleus becomes larger and 
more complicated. 
Description 
The earlier steps (figs. 2, 3, and 4) in the development of the 
several varieties of the giant-cells from the enlarged hemoblast 
(megakaryocyte, fig. 1) have already been considered above. 
Polykaryocytes arise from polymorphokaryocytes through the 
division of the lobulated nucleus of the latter. Certain of the 
isolated nuclei of the polykaryocyte may function as centers of 
intracellular differentiation of erythrocytes (fig. 9). Poly- 
karyocytes, moreover, suffer degenerative changes characterized 
by the aggregation of the chromatin of the separate nuclei into 
peripheral masses simulating equatorial plates of chromosomes 
(fig. 5). The originally distinct groups subsequently become 
mingled, a process seen at the beginning at the left of figure 5, 
and finally become scattered throughout the cell (fig. 6). The 
latter may occasionally show an arrangement of the chromatin 
segments (chromosomes?) like that of figure 15, simulating a 
multipolar mitotic figure like that of certain neoplastic cells; 
but neither centrosomes nor spindle fibers are here discernible. 
The chromatic rods of figure 6 subsequently become pale and 
granular and appear to dissolve within the disintegrating cyto- 
plasm. 
The giant-cell with basket nucleus (polymorphokaryocyte) 
also passes through early stages of degeneration by gradual 
steps as illustrated in figures 7, 8,9, and 11. The nucleus in the 
last of these stages becomes compacted into a spheroidal mass 
