MITOSIS IN POLLEN MOTHER-CELLS, 23 
THE TELOPHASE. 
As soon as the daughter chromosomes arrive at the poles, they 
approach each other very closely, so that, in many cases, the separate 
individuals cannot be recognized. But very frequently the segments 
do not become so closely crowded together, and the manner in which 
the daughter spirem is formed can be followed with accuracy. The 
formation of the spirem can best be observed when the granddaughter 
segments arrive at the poles in the form of the familiar V-shaped 
figures. Generally the ends forming the angles of the V fuse first, 
unless this has already been accomplished ; then the free ends meet end 
to end and unite (Fig. 10,G). In this, way there is formed a continuous 
single spirem in which the identity of the individual segments or 
granddaughter chromosomes is lost. 
If all the daughter chromosomes were regularly V- or U-shaped the 
spirem would be regular, consisting of an orderly series of nearly 
uniform turns; but the spirem rarely shows such regularity, because 
the chromosomes vary in size and shape and in the manner in which 
the granddaughter segments are oriented with respect to each other 
in the several pairs. During the reconstruction of the daughter 
nucleus, the chromosomes tend to reticulate, that is, to become 
irregular and lumpy, so that an irregular skein or net results. This 
is less pronounced in Zz/éum than in many other plants. 
The fact that pairs of granddaughter segments arrive at the poles in 
different forms, such as V’s, double U’s, and pairs of parallel rods, 
shows clearly that in such cases the resulting spirem must be very irreg- 
ular. The chromosomes are generally so closely crowded together 
that it is not possible to determine with certainty just how the variously 
shaped pairs of segments behave. But it is reasonable to suppose that 
the segments of the double U’s and those of contiguous rods must first 
separate in order to unite end to end, for no case has been clearly made 
out in £2/zZum in which a part of the spirem is formed double. 
The newly formed daughter spirem is close with relatively short 
turns (Fig.10,G,H). Between each twe extends the beautiful system 
of connecting fibers, which represents the central fibers of the spindle. 
Fibers are also present which extend from each spirem toward the 
plasma membrane in the direction of the equator. Some of these 
reach the plasma membrane, while others seem to end blindly in the 
cytoplasm, or pass over into its thread-work, In Lz/éum there are no 
polar radiations. 
The system of connecting fibers soon becomes barrel-shaped, and 
the cell-plate makes its appearance in the equatorial region, We 
shall return to the formation of the cell-plate beyond. 
