86 BOTANICAL GAZETTE [AUGUST 
where they converge at the apex. There is apparently no defi- 
nite position for the projection of each cone. They may be 
separated by considerable distance, or again there may be two or 
three quite close together (figs. 5, 6). The number also seems 
to vary, although there are always more than two formed. Cross 
sections always show three or four. Fig. 6 shows three on one 
side, and an indication of a fourth on the opposite side of the 
nucleus. This figure also shows that the growth of the various 
cones is not simultaneous. _ 
One of the striking features of the cones is the remarkably 
sharp point with which each one terminates. These sharp- 
pointed apices extend outward as the fibrils composing the cones 
elongate, and they indicate the outermost points at which are 
taking place the changes which bring about the transformation 
of the cytoplasmic reticulum into spindle-forming fibrils. 
As in Gladiolus, the nuclear membrane persists until the 
cones have almost attained their maximum development. In 
jig. 7 a portion of the nuclear wall remains, and several of the 
cones have fused together before the nuclear membrane entirely 
disappears. This fusion, however, probably does not begin until 
the nuclear wall begins to break down. When this is accom- 
plished the chromosomes become attached to the fibrils at the 
base of the cones. During and after this stage the collecting 
together of the cones was very noticeable. 
By the time the nuclear wall has entirely disappeared, and 
all the chromosomes are connected with the fibrils, the cones 
unite at their apices into several groups (fig. 8). Here three of 
these groups are represented, which are the product of the union 
of several primary cones. The space that was occupied by the 
nuclear sap is now filled with a complex of delicate fibrils, and 
all of the chromosomes are connected with fibrils which extend 
to the apex of one or other of the cones. By further union of 
the cones (figs. 9, zo), the number of cone aggregates is reduced 
to two. Up to and including the stage represented in fig. 9, the 
fibrils composing the cones were of the same general character, 
but in the following stages there is a differentiation of the fibrils, 
according to the part they take in the mature spindle. We have, 
2 a ee 
