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Entamoeba histolytica 
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form a compact mass on the plastin, Plate VII, fig. 6, while at other times they 
are irregularly distributed through the nuclear sap. 
During these changes the marginal chromatic band disintegrates into 
granules, which give a chromatin reaction to methyl green and other nuclear 
stains. 
Later there is extrusion of chromatin grains into the cytoplasm. Plate VII, 
Fig. 10, shows this process; the central mass of the nucleus has aggregated to the 
side from which extrusion is taking place. This is not always the case, however, 
for often the karyosome remains centrally situated. The study of many 
preparations showing this phenomenon has convinced me that the extruded 
chromatin is derived from that found on the nuclear membrane. 
On reaching the cytoplasm the granules usually aggregate into an irregular 
number of small bodies, figs. 7, 11, 12, 14, which often persist until the nucleus 
has divided, fig. 22. Their chemical nature seems, however, to undergo a 
change, for when extrusion occurs, as in fig. 10, they stain a distinct purple 
with Fleming’s tricolour stain and green with methyl green; but on reaching 
the cytoplasm, as in figs. 7, 11, 12, 13, 14, they stain red with the tricolour 
stain and remain unaffected by methyl green. 
After this process the nucleus becomes smaller and appears as a lightly 
stained body with a few peripheral granules. In the centre there is a distinct 
plastin body, with granules, figs. 12, 13, or the granules lie between the 
plastin body and the nuclear membrane, figs. 7, 14. On occasion two of these 
grains can be seen side by side as in fig. 15, and could be interpreted as the 
two portions of a divided centriole. I believe that figures similar to this led 
Hartmann to the conclusion that centrioles are found in the dividing nucleus 
of E. histolytica. I may state at once that I have found no justification for 
such a view. 
Finally another variation occurs where in the centre of the nucleus there 
is the plastin body with a few granules and the remainder on the periphery, 
Plate VII, figs. 2, 11. 
Division stages are extremely rare and I had to examine very many indi¬ 
viduals before I was able to work out the different phases. I endeavoured to 
watch the process in the living animal but with no success. On two occasions 
I was able to see the division of the animal, but as the nucleus was not visible 
during the process it was impossible to note the details. The following descrip¬ 
tion is therefore based entirely on stained preparations. At the beginning 
the nucleus elongates and some of the peripheral chromatin becomes massed 
together at each pole. The plastin mass in the centre also elongates and the 
chromatin grains aggregate together on and around this body, Plate VII, figs. 
4, 16. Very fine spindle fibres are formed radiating from one end of the nucleus 
to the other, Plate VII, fig. 17. I have not been able, however, to discover from 
what part of the nucleus these fibres are produced. The chromatin granules 
arrange themselves on the spindle fibres and finally approximately equal 
numbers pass to each pole of the nucleus; at the same time the plastin body 
