13 Similar cell at a comparable stage, from the angioblast layer of the yolk- 
sac of a 10-mm. pig embryo. Zenker fixation; hematoxylin and eosin stains. 
14 and 15 Suecessively later stages in the process of disintegration initiated 
in figures 11 and 12. In the seriation of mitotie stages described for these cells 
by Denys, figure 15 represents an intermediate stage (‘metaphase’) between fig- 
ure 6 (‘prophase’) and figure 5 (‘telophase’). Neither centrosomes nor spindle 
fibers are discernible. 
16 <A variety of polykaryoecyte in which many of the nuclei are relatively 
small. This cell corresponds with stage | in mitosis as described by Dickson. 
17. Very rare variety of polykaryceyte, in which all of the nuclei are of 
approximately uniform size and relatively very small. This type of cell corre- 
sponds with stage 2 of Dickson’s seriation of steps in mitosis. 
18 Later stage in the disintegrative process as shown beginning in figure 17. 
A row of small nuclei is still discernible at the right. At the left the chromatin 
of the nuclei has coalesced to form a very coarse and irregular chromatic network 
or ‘spireme.’ This type of nucleus is almost bare of cytoplasm. 
19 Still later stage in the process of disintegration of this giant-cell. This 
type of nucleus is quite naked. The cytoplasm has become used up in the pro- 
duction of blood-platelets. 
20 A variety of polymorphokaryocyte in which the lobulated nucleus 
appears homogeneous for the most part and stains very intensely. This type of 
nucleus signifies beginning disintegration. Such a cell produces platelets by 
fragmentation of large areas of its cytoplasm. This type of cell corresponds 
with a distinct phase of the division of these giant-cells as described by Arnold 
as ‘indirect fragmentation.’ 
21 and 22 Suecessively later stages in the process of disintegration of this 
variety of cell, leading to a naked and ultimately fragmenting nucleus. The 
nucleus in figure 21 is enveloped by only a narrow layer of cytoplasm, fragmenting 
peripherally. 
23 and 24 Suecessively later stages in the process of disintegration of origin- 
ally polymorphous nuclei, compacted and modified through loss of cytoplasm in 
the formation of platelets. Figure 23 is comparable to 18, and may be derived 
from cells like those of figures 16 and 17. Figure 24 is also comparable to figure 
18, and represents a variety of this type of nucleus. 
25 Multinucleated giant-cell from the enamel pulp of a new-born cat. These 
cells are formed by the fusion of originally discrete, mononucleated cells of the 
enamel organ. They may contain globules of resorbed enamel. The cytoplasm 
is acidophilic in staining reaction. Zenker fixation; hematoxylin and eosin stains. 
26 Early stage in the disintegration of these enamel giant-cells. The chro- 
matin of the nuclei collects in several peripheral crescentic masses and occa- 
sional spherical or elongated dropiets. The nuclei become pale, their membrane 
eventually ruptures, and the chromatic masses are cast out into the cytoplasm of 
the disintegrating cells where they simulate prophase chromosomes. 
27 Late stage in the disintegration process. The chromatic masses (chromo- 
some simulacra) eventually dissolve within the fragmenting cytoplasm. 
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