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go BOTANICAL GAZETTE [aveusr ‘ 
of the spindle, but the process of forming a wall seems to go no further; : 
indeed, it very seldom proceeds to this point. 
That the second mitosis succeeds the first very closely is attested — 
by the fact that examples of both divisions are frequently found :, 
in the same capsule. The spore mother cells of a given capsule are 
in division at the same time, though not exactly in the same phase — 
of mitosis. Occasionally cells are found which lag considerably : 
behind or precede the majority in division. Such cases are of great — 
value in determining stages with certainty. . 
The spindles for the second mitosis make their appearance very : 
suddenly, and I have not been able to determine their origin. They — 
are quite strongly developed, and as a rule are longer and narrower “ 
than the spindles of the first mitosis. The passage from the meta 
phase to the telophase is almost as rapid as in the first division, and 
no additional evidence is afforded as to the manner in which the — 
chromosomes separate. Fig. 21 illustrates metaphase of the two — 
spindles, showing a polar and a side view. In this example the poles — 
of the spindles are sharply pointed. In fig. 22, which represents a0 
anaphase, the poles are blunt. The chromosomes pass rapidly to 
the poles and are grouped at the two ends in rings (igs. 23 and 24). : 
At this stage the fibers are very prominent in transverse sections of the 1 
spindle (jig. 24). ‘ 
Soon after the chromosomes have passed to the poles, gran 
make their appearance upon the equatorial region of the spindle (/ 
24). These become divided and a cell plate is laid down between 
them (jig. 25). Meanwhile the nuclear membrane is formed andt 
chromatic elements pass over into the reticulum characteristic of t 
resting state. - 
Finally, the new cell plates unite with the folded walls 
the lobes and the separation of the spores is complete (/ig. 26). =e 
contiguous walls split apart and the spores become free. Th 
next increase in size, becoming almost spherical, and the wall thickens 
and is finally marked with delicate points (fig. 27). 
The spores do not germinate in the capsule as do the spo! 
Pellia. Soon after being shed, they increase greatly in size, stretc 
the wall, as is clearly shown by the separation of the points Up? 
surface. After the cell has attained a size several times that 
