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DOEIS L. MACKINNON. 
Fig. 9. — A later stage of fig. 8. The migrating nucleus approaches 
the posterior end of the body. 
Fig. 10. — “Tailed” individual of Polymastix. 
Fig. 11. — “ Forked ” individual. 
Fig. 12. — Preparation for encystment. Peidplast fraying off, flagella 
disappearing. Nucleus has taken up a central position. 
Fig. 13. — “ Deformed ” individual with displaced nucleus. Possibly 
an early stage of encystment. 
Fig. 14. — “ Ribs ” of the periplast fraying off. In this condition they 
look very like adherent bacteria. 
Fig. 15. — Encysting Polymastix. The flagella have disappeared, 
and the nucleus has moved to the centre of the body. 
Fig. 16. — Encysting Polymastix. A rather later stage. The ribs 
of the periplast have almost all disappeared. Note the basal granules, 
surrounded by a clear zone. 
