308 H. E. JORDAN 
In figure 27 we meet with a still later stage in this same degen- 
erative process. The cytoplasm at certain points on the pe- 
riphery appears to be disintegrating. Meanwhile the chromatin 
masses have become scattered throughout the cytoplasm. Near 
the center may be seen what appears to be the origin of paired 
chromatic rods by outflow of chromatin from a nuclear vesicle. 
These chromosome-simulacra may by chance become arranged 
in certain portions into configurations suggesting multipolar 
spindles of cancer cells. In certain portions they become more 
closely massed into a fine-meshed chromatic network. Certain 
of the chromatic rodlets fragment, and certain masses lose their 
deep-staining capacity. Eventually all of this chromatin dis- 
solves within the disintegrating giant-cell cytoplasm. The close 
correspondence between the phagocytic syncytia of the enamel 
pulp and the multinucleated giant-cells of red bone-marrow is 
striking. These two types of giant. cells have, however, an 
entirely different origin and function, but in their later disinte- 
erative stages they present comparable aggregations of chro- 
mosome-simulacra, derived in very similar manner in both 
instances, and clearly in both cases indicative of degeneration. 
SUMMARY 
1. The red bone-marrow of the rabbit and the guinea-pig 
contains three chief varieties of giant-cells: megakaryocytes, the 
monoucleated forms derived by excessive growth from the 
hemoblast; polymorphokaryocytes, the forms with polymor- 
phous or lobulated nucleus derived from the megakaryocyte by 
incomplete direct division of the nucleus, and polykaryocytes, 
the multinucleated forms derived from forms with lobulated 
nuclei by completion of the constrictions in the complex mucleus 
to produce separate smaller and spheroidal nuclei. Comparable 
varieties with similar genetic history occur also in the yolk-sac 
of the pig embryo. 
2. Certain giant-cells of the multinucleated variety, chiefly 
bi- or quadrinucleated, retain to a small degree the capacity of 
their original hemoblast ancestor of producing intracellular 
erythrocytes. In these giant-cells erythrocytes may differen- 
tiate intracellularly about isolated nuclei. 
