BoT— Vol. I.] LAWSON—COB^A SCANDENS. 1 77 



reached the poles the mantle-fibres immediately lose their 

 straight appearance and hang loosely alongside of the 

 remaining continuous fibres, as shown in fig. i8. They 

 soon after disappear. Although the continuous fibres now 

 curve out towards the cell-wall as shown in fig. 19, there is 

 no cell-plate formed until after the second division. 



When the dauofhter-nuclei have surrounded themselves 

 with a membrane the continuous fibres still persist, being 

 attached to the daughter-nuclei as shown in fig. 19. In 

 this figure we also see that the perikaryoplasm appears to be 

 more plentiful at the ends of the cell where the nuclei lie. 

 It surrounds the nuclei except where the continuous fibres 

 are in connection with the nuclear membrane. The peri- 

 karyoplasm gradually surrounds the nuclei and apparently 

 cuts off the continuous fibres. As shown in fig. 20, they 

 can no longer be traced to the nuclear wall, and the 

 perikaryoplasm has formed a complete zone about each 

 nucleus. 



The development of the spindle of the second division is 

 identical with that of the first division, but on account of its 

 small size, the stages in the process are much more difficult 

 to work out. 



In fig. 21 we see the last traces of the continuous fibres, 

 and each of the nuclei is surrounded by a granular zone. 

 It will also be noticed that the black bodies have formed 

 rings at the outer margin of the zones of perikaryoplasm, 

 just as they did in the case of the first division. These 

 zones are as well defined and differentiated from the rest of 

 the cytoplasm in structure and staining properties as in the 

 first division. 



In fig. 22 we see the two spindles of the second division 

 lying at right angles to one another. In one the spindle is 

 represented only by the cross-sections of its fibres. The 

 other shows the entire spindle with the characteristic mantle- 

 fibres, and the chromosomes on their way to the poles. 

 This figure also illustrates the fact that the perikaryoplasm 

 accommodates itself to the shape of the spindle. In one 



