PLATE 7 



Fig. 23. Chromosomes appearing in the nucleus before other signs of division 

 can be detected in the body. Figures 25-29 were drawn from similar individuals. 

 X 300. 



Fig. 24. Bounding up of the body preparatory to division; part of the centro- 

 blepharoplast complex and alveolar layer shown. X 300. 



Fig. 25. — Longitudinal division of the chromosomes. 



Fig. 26. — Breaking up of the chromatin-encrusted network beginning at one 

 side of the nucleus. 



Fig. 27. Network thickly encrusted with chromatin showing free ends. 



Fig. 28. Later stage of the same with the threads beginning to split. 



Fig. 29. Chromosome formation nearly completed. 



Fig. 30. Beginning of division of the centroblepharoplast complex. Note the 

 spindle-shaped areas of endoplasm appearing between split. 



Fig. 31. Optical section of rounded-up individual of the prophase period. 

 X 300. 



[88] 



