MITOSIS 



35 



to move apart. As they move they seem to leave a vacant, cone-shaped 

 area between themselves and the nuclear membrane. The outer bound- 

 ary of this space seems to be the 

 straight rays from the centro- 

 some, which are very well devel- 

 oped and are numerous enough 

 to form a continuous boundary 

 (Fig. 39). A new and weaker 

 set of radiating fibrils appear in 

 this space, and reach from near 

 the centriole to the nuclear 

 membrane, upon which they 

 appear to have some destructive 

 influence. This membrane be- 

 gins to curl where so influenced, 

 and in the next figure (40) it is 

 shown as very much degener- 

 ated. 



This figure also shows the 

 chromatin spireme broken up 

 into a certain number of long, 

 bent chromosomes, which are not yet arranged in the equatorial 

 position which they must occupy before they can be drawn apart 



FIG. 39. Later stage than Fig. 38. Irregular 

 spireme, centrosomes moving apart and nuclear 

 membrane beginning to fail where touched by 

 the forming spindle fibrils. 



FIG. 40. Later stage of this mitosis. Nuclear membrane nearly gone. Spireme breaking to 

 form chromosomes. Spindle fibrils growing towards each other. Nucleolus almost gone. 



in longitudinal halves. The spindle fibrils which were so weakly devel- 

 oped in Figure 39 are here seen to be more strongly developed than 



