370 BOTANICAL GAZETTE | DECEMBER 
which is entirely independent of external tension; and the same 
inference is possible from the gradual shortening of the spirem 
to form the chromosomes, and from the re-expansion of the 
chromatin in the daughter nuclei. 
Meanwhile, the outer region of the cytoplasm loses its reticulate 
structure (still evident in figs. 3, 4), and passing through a con- 
dition in which it appears to be a diffusely staining mass becomes 
converted into granules, as in figs. 8 and g. This change, which 
is comparable to that preceding the organization of the kino- 
plasm into fibrillae, advances gradually from the spindle out- 
wards towards the cell wall. Directly after the metaphase the 
granules of this outer zone arrange themselves into rows stretch- 
ing from the poles out towards the equatorial region of the cell. 
This condition is shown in fig. g, and again in the second division 
in figs. 77 and 78. These rows of granules, which soon become 
more threadlike, will be spoken of as secondary fibers, to distin- 
guish them from the primary fibers that form the central frame- 
work of the spindle. They are not mantle fibers, for they do 
not enter into connection with the chromosomes, and are only 
just coming into existence when the latter begin to withdraw 
from the equatorial plate towards the poles. The secondary 
fibers multiply rapidly, and by the end of the anaphase fill all 
the outer part of the cell; in fact all the cytoplasm seems to 
have been exhausted in producing them. 
Almost immediately there begins a breaking down of the 
spindle fibers, indicated in the first place by their reassuming 
the appearance of dotted threads. In all cases the primary 
spindle is the first to disappear; then the secondary fibers break 
down and all the stainable cytoplasm is of granular texture ( figs: 
71,13). Acell plate is first formed, which however comes to 
nothing ; it can be traced through figs. 12-18, 21. 
Though the second division follows quickly after the first, 
there is a sufficient interval between to allow the mere 
of a nuclear membrane and the partial reorganization of ee 
chromatin. The chromosomes after assuming a very eer 
cal pattern about the poles unite into a chromatic mass wht 
