ANIMAL AND VEGETABLE 115 



till they reach the equatorial plane of the spindle, where 

 they constitute the nuclear disc, and are so placed that 

 their free ends point to either one pole or the other. Whilst 

 these changes have been going on, the nucleoli have dis- 

 appeared, being diffused in the nuclear ground-substance. 

 The fibrils now undergo longitudinal splitting into two, 

 and then the nuclear disc separates into two halves, in such 

 a way that one of each pair of fibrils produced by the 

 splitting of each primary fibril goes to each half. The 

 fibrils constituting each half of the nuclear disc now move 

 towards the corresponding pole along the spindle-threads, 

 changing their position as they go, so that when they 

 reach the pole their free ends point towards the equatorial 

 plane. On reaching the pole, each group of fibrils con- 

 stitutes a new nucleus ; it becomes invested by a mem- 

 brane, nucleoli reappear, and the fibrils resume the form 

 and structure of the resting nucleus. The two nuclei are 

 now completely formed, and are still connected by kino- 

 plasmic spindle-threads " (as in Fig. 17). " If no cell- 

 division is immediately to take place, no further change 

 occurs beyond the disappearance of the threads," and this, 

 it will be noted, is the stage immediately preceding division 

 in ordinary mitosis. 



It is interesting to compare this account of vegetable 

 cell -reproduction with that given by Schafer of mitotic 

 division of the animal cell. The wording is different, but 

 the processes appear to be identical. 



