a eR Ee ee ge ney 
1899 | STUDIES ON REDUCTION IN PLANTS 15 
becomes the point of the V-shaped daughter chromosome, or 
forms a slight projection on the convex side of the U-shaped 
ones if this form is retained. No pull is exerted on the end of 
the chromosome, the ends of the pairs remain united, or in 
position at the periphery of the nuclear plate, while the middle 
portions are drawn toward the opposite poles, and in opening 
out thus, the dividing chromosome forms the diamond-shaped 
figure when seen from in front (fig. 78). 
During the anaphase the chromosomes are V-shaped or 
U-shaped, and show considerable irregularity in contour, being 
more or less nodulose, often showing still the four dense 
chromatin masses. Some close up behind and form rings, 
some divide in front and form two rods. As the chromosomes 
approach the poles the polar ends converge, so that the chromo- 
somes lie close together around the periphery of the ends of the 
spindle. Lying in this position the daughter nucleus is formed. 
The form ofthe daughter nucleus is somewhat like the half ofa 
biconvex lens, the convexity being outward, while the truncated 
end lies toward the cell plate now formed by the connecting 
spindle threads. The form and position of the chromosomes 
give to the daughter nucleus its shape, for as the closed ends 
of the V- or U-shaped chromosomes converge at the apex of 
the cone, the spreading arms of the open end cause the nucleus 
to broaden out on the side facing the cell plate. The nuclear 
cavity now appears and the chromosomes are lying on its 
periphery against the nuclear membrane. They become usually 
more irregular in form, with angular points on the edge to which 
appear to be attached delicate threads connecting with the 
nuclear membrane, or reaching to an adjacent chromosome. 
Where the nucleus is small by the close crowding of the 
large chromosomes, it is quite impossible to determine whether 
the chromosomes unite in such a way as to form a spirem. The 
nucleus does not, however, pass into a resting stage with the 
linin reticulum upon which the chromatin is distributed, but the 
chromatin bands remain intact. In the large nuclei, where the 
chromosomes do not lie so close together, they appear in most 
