1903] MITOSIS IN PELLIA as 
During the early prophases the poles of the spindle are usually — 
rounded (figs. 3, 4, 6), but, as the metaphase approaches, the 
caps (figs. 3, ¢) which have given the poles of the spindle a 
rounded form become resolved into fibers, and the poles may 
vary in shape from sharply-pointed figures, like that shown in 
jig. 10, to such broad, indefinite ones as those shown in figs. 8 
and 27. Spindles with three and even more poles are not very 
rare. They do not originate like the multipolar spindles of the 
Spore mother-cells of vascular plants, but are preceded by the 
bipolar condition or are formed through the influence of three or 
more centrospheres or asters (figs. 76, 23). During the ana- 
phases the poles of the spindle are sometimes sharp and some- 
times indefinite. 
In the prophases it is plain that the achromatic figure is made 
up of the asters and two half-spindles (fig. 6). As the spindle 
continues to develop, some of the fibers—the mantle fibers— 
become attached to the chromosomes; the other fibers increase 
in length until they reach the opposite pole, thus forming a part 
of the central spindle. 
While the poles are separated from each other, radiations are 
easily seen, and they continue to be fairly conspicuous until the 
spindle has reached its full length, when they rapidly disappear, 
losing their staining capacity first at the peripheral ends, then 
throughout their entire length, and finally becoming indistinguish- 
able. When the metaphase is reached, the radiations have usually 
disappeared (fig. 7), and during the anaphases, while the chro- 
mosomes are passing to the poles, it is very seldom that any 
trace of radiations can be found. In the telophases, however, 
the radiations reappear, but are not centered in any single point. 
When the nuclear membrane begins to form, the radiations again 
become indistinct and disappear as before. Just before the 
Spindle reaches its full length (fig. 6) the radiations often attain 
their greatest prominence, sometimes appearing as extremely 
Coarse strands. In nearly all cases, even in very thin sections, 
Some of the rays can be traced from the pole of the spindle to 
the Hautschicht. The diameter of the rays is usually greater at 
the polar end, but a slight increase in diameter at the Hawuéschicht 
