GIANT-CELLS OF BONE-MARROW 305 
Another fact must be taken into consideration in this connec- 
tion, namely, the division of the centrosome into a_pluricor- 
puscular body, and next the scattering and finally the disappear- 
ance of these elements concomitantly with successively later 
steps in the degeneration process as judged by the condition of 
the nucleus. When one keeps in mind the fact that the giant- 
cell suffers a continual diminution of its cytoplasm through 
the formation of blood-platelets, the invariably smaller size 
(see also Denys’ figures) of the cells with the later nuclear 
degenerative changes simulating groups of chromosomes becomes 
intelligible. 
The question arises as to whether the nucleus undergoes 
degenerative changes because the cytoplasm is gradually being 
eliminated in the formation of platelets or whether cytoplasm 
is being discarded and platelets incidentally formed because the 
nucleus suffers degeneration, or whether both events are the 
combined effects of the same fundamental cause. The most 
plausible interpretation, in view of all the facts, includmg the 
data previously derived from a study of giant-cells of the yolk- 
sac and of frog’s marrow, is as follows: As the result of the 
operation of some unknown factor, certain hemoblasts enlarge 
to form the simplest type of giant-cells. This enlargement dis- 
turbs the optimum nucleocytoplasmic relation. In an attempt 
to recover this original optimum relation, pseudopods are pro- 
jected; these constrict and break up into platelets and the cyto- 
plasmic volume relative to the nucleus is thus reduced. The 
same end may be served by the nucleus, through increase of its 
bulk and its surface area, by enlargement, lobulation and finally 
direct division. The disturbance of optimum nutritive condi- 
tions operating meanwhile works an untoward effect upon the 
centrosome which in consequence fragments into a pluricorpus- 
cular centrosome. Failure to cope with the factors effecting 
interference with the optimum nucleocytoplasmic relation 
initiate gross degenerative changes expressed on the part of the 
cytoplasm by mass fragmentation, and on the part of the nucleus 
(as in fig. 4) by an aggregation of the chromatin in peripheral 
droplets (fig. 5). Subsequently the nuclear membrane disap- 
THE AMERICAN JOURNAL OF ANATOMY, VOL. 27, NO. 3 
