Bull. U. S. B. F., 1926. (Doc. 987) 
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Figs. 17 to 19. — Successive stages in the development ot the cyst nuclei. The nuclear membrane 
Figures 18 and 19. X 1640 
Fig. 20. — Optica lsection of a cyst showing typical arrangement of the nuclei. X 1800 
Fig. 21. — Small cyst with five nuclei drawn at a higher magnification to show details of structure. 
Fig. 22. — Optical section of cyst with a mass of chromatoidal bodies on one side. X 1800 
Figs. 23 to 26. — Cysts showing successive stages in the division of the nuclei. Prophases. X 2700 
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