292 Ma rquette, Manifestations of polarity in plant cells which usw. 
they are more evenly distributed, as a resnlt the figure appears 
lighter in the middle than at the ends. The cell from which figure 
6 is taken shows in addition to tliis a narrow light streak across 
the equatorial region of the connecting fihers which is not repro- 
duced in the figure. Whether this light streak is a regulär 
occurrence in connection witli cell-plate-formation and what its 
relation is to Timberlake’s r ) ..orange zone“ I have not determined. 
When the chromosomes have about reached the poles and are 
crowding closer and closer together tliey accupy a space which in 
section is approximately kidney shaped, the concave side facing 
the pole. Soon the new huclear membrane appears, the daughter 
nuclei steadily increasing in size during this period. The chromatin 
for a time appears to be arranged in a more or less spiral fashion, 
the irregulär contours of the Strands indicate that it is in process 
of being distributed through the nuclear cavity. (Fig. 7.) The 
nucleoles also make tlieir appearance at this stage. The first in- 
dication of tlieir presence is the appearance of from one to several 
faintly staining masses lying between the material of the chromo¬ 
somes- At first the boundaries of tliese masses are indistinct 
gradually passing over into the clear nuclear sap, later however. 
they become more and more definite, and at the same time the 
affinity of the material of the masses for stains increases until 
finally completely formed nucleoles are present. 
During tliese changes in the daughter nuclei the polar structures 
have considerably increased in size. Frequently at tliis time the 
starch contained in them stains with especial intensity so that the 
wliole cell with its violet chromatin, blue gray connecting fibers, 
and deep blue starch grains presents a striking appearance. 
As was previously mentioned the content of any particular 
starch body seems to fluctuate with the stages of cell-division, but 
it is difficult to decide with certaintv whether tliere is more starch 
in a cell at any particular stage of mitosis than at another because 
of the great individual variations between cells in regard to tlieir 
starch content. The indications are, however, that the starch 
decreases in amount during the propliases and that tliat which is 
present comes to stain less intensely. This condition continues 
until into the telopliases when the starch grains again appear to 
become more numerous, and also to take a deeper stain. That 
such a periodic fluctuation in the starch content of the polar 
structures actually exists is made probable by the fact tliat in 
examining a large number of preparations it is onl^v liere and there 
that a cell appears which shows abundant starch in tlie anaphases 
or in the late propliases at the sanie time one frequently finds 
cells in the telopliases wliose polar structures are closely packed 
with starch. This Observation would be fairly convincing as to a 
consumption of starch during spindle formation. possibly also during 
the time tliat the chromosomes are passing to the poles, and its 
J ) Timberlake. H. Gr: TJie development and function of tlie cell plate 
in higher plants. (Bot. Graz. Vol. XXX. 1900. p. 97.) 
