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1903} GAMETOPHYTES AND EMBRYO OF TAXODIUM I 
of the egg after fertilization. In fig. 28 a number of scattered 
Starch grains have made their appearance in the cytoplasm of 
the central cell. They retain their scattered position until 
finally arranged into the dense starch sheath immediately 
surrounding the nucleus of the sperm-cell. 
Changes in the nucleus preparatory to the final division of 
the central cell had already begun at the stage represented in 
fig. 27. In fig. 28 these changes have proceeded still further. 
The chromosomes are being prepared from the few thick con- 
spicuous threads that are present. The linin granules have 
become organized into a reticulum, and this reticulum seems to 
be arranging itself as if in the preparatory stages of spindle 
formation. 
No attempt was made to study in detail all stages of spindle 
formation in the division of the central cell, but in fig. 29, which 
shows an oblique view of the spindle, the formation of its fibers 
from the nuclear reticulum and the granular nature of the more 
peripheral fibers seems evident. This formation of the spindle 
from the fibers of the nucleus will be described in more detail in 
the division of the ventral canal cell. Fig. 30 shows a late 
telophase in the division of the central cell, the connecting 
fibers still being evident. A clear area is noticed on each side 
of the cell plate, and this area later extends entirely around the 
sperm cells, The starch and plastin material are collected at the 
distal ends of the spindle, but after the separation of the two 
daughter cells the starch becomes arranged in a dense sheath 
immediately surrounding the nucleus (fig. 37). Just outside of 
this sheath the plastin granules form a more or less complete 
layer. Beyond them is found the clear area previously mentioned, 
and the surface is composed of a distinct membrane which sharply 
defines the sperm cells from the protoplasm of the tube. After 
the formation of the daughter nuclei, they again begin to fill 
with the linin granules or reticulum (the so-called metaplasmic 
substance of Strasburger ) until, at the time of maturity, they are 
So dense as to make any distinction between the granular materia] 
and chromatin reticulum very difficult. A small nucleolus, 
however, can be dimly discerned (fig. 37). 
