470 
DOlUS L. iVlACKlNNON. 
Fig. 13. — The nuclear outlines become vague; the karyosome frag- 
ments; the rhizostyle has doubled. 
Figs. 14-16. — Formation of the spindle. In fig. 16 a certain amount 
of chromatin has already collected at the poles. 
Figs. 17-20. — The chromatin collects at the poles. The spindle thins 
out more and more. 
Fig. 21. — The spindle has disappeared. Two compact nuclei are left. 
Figs. 22-26. — Various aspects of the cyst with two nuclei. In fig. 22 
the large vacuole has disappeared. In fig. 26 one of the nuclei has 
taken on the vesicular form, and the cyst has elongated. 
Figs. 27-29. — Small flagellates with eccentric nucleus. Possibly 
these have recently emerged from cysts. Fig. 29 shows an individual 
with three nuclei. 
Figs. 30-33. Tetra tri chomastix parisii. 
Fig. 30. — Form A. Note fully developed axostyle and dark-staining 
nucleus with large chromatin masses. 
Fig. 31. — Form A. Note halo (H.) of drop-shaped bodies surrounding 
nucleus. 
Fig. 32. — Form B. Note relatively large, faintly staining nucleus, 
poor in chromatin. 
Fig. 33. — Form B. 
Flagellate without axostyle. 
