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axis of the cell the nucleus has a central position, but in sections 
parallel with that axis it is always excentric and sometimes lies in 
an out-pocketing, as it were, of the cell. The side of the nucleus 
away from the periphery of the cell is frequently flat or even slightly 
concave (Figs.9—11). This characteristic was noted by both v. LENHOSSER 
and DEHLER for the cells of the frog which they described. To this 
flattening the inequality of the axes of the nucleus is due. Occasion- 
ally two nucleoli are present, but usually only one, which is very 
large. Where two are present, one is considerably larger than the 
other. | 
At one side of the nucleus — the one toward the center of the 
cell and the one which tends to be flattened or concave — are found 
the structures which, following v. LENHOSSEK, may be called centrosome 
and sphere. The sphere varies somewhat in size, but its diameter is 
approximately one third that of the cell. In some cases it is quite 
sharply marked off from the surrounding protoplasm of the cell; in 
other cases the transition to the surrounding protoplasm is so gradual 
that is impossible to define its limits with precision. Passing from 
without inward there are encountered in this sphere (Figs. 5, 8) first, 
a broad zone of coarsely granular protoplasm; within this a smaller 
area of more nearly homogeneous protoplasm; and in the center of 
this a very small highly refractive body, or occasionally two or three 
such bodies. From this central corpuscle (Figs. 5, 6, 7, 8, 10) there 
are in many preparations radiations which traverse both the inner, 
more homogeneous zone and the outer, coarsely granular zone. 
Sometimes the radiations pass even beyond this into the surrounding, 
finely granular protoplasm of the cell. The rays, though represented 
diagramatically in the figures as though composed of coarser granulations, 
are in reality not such at all, but are due to the closer arrangement 
in radiating lines of granulations of the ordinary size. Some of the 
rays are very distinct, others much less clear. They are few in 
number, usually separated by rather uniform intervals, but often 
interrupted over an arc of many degrees. 
The central corpuscle (or corpuscles) is very distinct. It is sometimes 
spherical, sometimes elongated so as to look like a short rod. It 
shows a remarkable affinity for stains, being always colored much 
more deeply than any other part of the sphere. Indeed, in many 
preparations it seems to stain as deeply as the nucleolus. Figure 7, 
which represents one of the clearest vom RATH preparations, shows 
a single spherical corpuscle. Figures 5 and 6, which are successive 
sections of one cell, represent preparations by the vom Rats method. 
