1 88 CALFFORNIA ACADEMY OF SCIENCES. [Proc. 3D Skr. 



EXPLANATION OF PLATE XXXVL 



Fig. 19. Here we see each of the daughter-nuclei surrounded by a 

 membrane, with the chromatin stained blue, and in the form of 

 a necklace. There is also seen a nucleolus in each daughter- 

 nucleus. The continuous fibres still connect the nuclei with 

 one another. The granular substance appears to surround the 

 nuclei e.xcept where the continuous fibres are coimected with 

 the nuclear membrane. 



Fig. 20. The perikaryoplasm now entirely surrounds each daughter-nucleus. 

 The connecting fibres have curved out toward the cell-wall but 

 can no longer be traced to the walls of the nuclei. 



Fig. 21. The old spindle-fibres have disappeared and each of the daughter- 

 nuclei is surrounded by a definite zone of perikaryoplasm. The 

 black bodies form a ring at the outer margin of each zone. 



P'ig. 22. This figure shows the two spindles of the second division lying 

 at right angles to one another. The one is only represented 

 by the cross-sections of its fibres, the other shows the entire 

 spindle with the chromosomes on their way to the poles and 

 with the characteristic mantle-fibres. This figure also shows 

 that the perikaryoplasm has accommodated itself to the 

 shape of the spindles. In one view the zone is round and in 

 the other oblong, corresponding to the size and shape of the 

 spindle. 



Fig. 23. Here the spindles of the second division are more nearly in the same 

 plane than in the preceding figure. The chromosomes are at 

 the poles. The mantle-fibres of the two spindles have reached 

 over and united, thus connecting the nuclei with one another. 



Fig. 24. Here we see three of the daughter-nuclei in the same plane, each 

 surrounded by a nuclear wall. The chromatin is in the spi- 

 reme stage. All the daughter-nuclei are connected by fibres 

 which almost fill the entire cell-cavity. These fibres are curxed 

 out toward the cell- wall, and we see swellings on some of them. 

 What little of the perikaryoplasm is left is scattered irregu- 

 larly through the cell. 



