436 



XXXII. CELL-DIVISION AND NUCLEAR DIVISION. 



numerous in the two opposing groups. Since the stage in which 

 we saw the coarsely granular, obliquely arranged threads (2) 

 about an hour may have elapsed. The nuclear segments appeal- 

 almost homogeneous ; but with a higher power we can recognise 

 slight constrictions on the surface, which indicate construction 

 out of successive discoid pieces of chromatin substance, between, 



FIG. 153. Tradescantia Virgitiica. Processes of division in the cells of the 

 staminal hairs. Fig. 1, with a resting nucleus in its lowest cell, and an upper cell 

 which has just divided. Fig. 2, with a coarsely granular nucleus showing oblique 

 striation. Figs. 3-11, successive stages of division followed in the same cell ; 3, about 

 10-10 o'clock ; 4, 10'20 ; 5, 10'25; 6, 10'30; 7, 10'35; 8, 10-40; 9, 10'50 ; 10, 11-10; 

 11, ll'30(x 540). 



and connecting, which is linin. With only limited time at our 

 disposal we can choose this as the best stage to begin continuous 

 observation. We have now to look for the separation of the two 

 nuclear halves in the course of the next few minutes, and this 

 proceeds so quickly that we can see it take place. The two 

 nuclear halves remove from one another in longitudinal direction 



