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Hata, Mitosis in Nerve Cells. 285 
Fig. 10 is a somewhat polar view of the mitotic figure in 
the metaphase. The continuous segmented spireme shows, in 
most cases, a modified dumb-bell shape as was mentioned 
above. Fig. 7 isa polar view of the equatorial plate drawn in 
optical section. This figure presents also a modified segmented | 
spireme. Fig. 8 is a cross section of the mitotic figure passing 
through a plane near the middle of the equatorial plate. The 
continuous chromosomes were cut in such a way as to present 
discontinuous V-shaped bedies. The nucleolar substance which 
thickly surrounds the chromosomes, and also the radial arrange- 
ment of the same substance from the center toward the periph- 
ery, are distinctly visible in the space surrounded by the chrom- 
osomes. This radial arrangement of the nucleolar substance is 
much more clearly noticeable in Fig. 7. 
B. Germinal Cells in the Metaphase. In this phase the 
chromosomes forming the equatorial plate lose their regular 
arrangement and lie somewhat irregularly in the equator of the 
cell-body (Figs. 11 and 12). Meanwhile with this change, each 
internode of the continuous segmented spireme splits along its 
long axis. This split, however, stops at the terminal enlarged 
bulbs; that is, both extremities of the dumb-bell remain un- 
divided. In some cases, these terminal bulbs show deep con- 
Strictions along the middle, as can be seen in Fig. 11. Curi- 
ously enough, when each internode divides longitudinally, then 
new enlargements or knobs are produced, one on each side near 
the middle of each daughter chromosome. This is indistinctly 
visible in Fig. 11, but plainly shown in Fig. 13. When the 
chromosomes split longitudinally, the nuclear substance still 
surrounds the figures, except in very few cases where the nu- 
cléolar substance is only visible surrounding each daughter 
chromosome, but does not fill up the space newly formed by 
the splitting. After the splitting processes have been com- 
pleted, the continuously segmented spireme rearranges itself in 
a manner different from the equatorial plate (Fig. 9) already 
mentioned; that is, the enlarged portion of the dumb-bell in 
Fig. 9g lies along the equator of the figure, and the knobs 
newly formed at the middle point of each daughter chromo- 
