PLATE 26 

 All figures of Giardia enterKa (Grassi) from human stools. X 3200. 



Fig. 23. Early prophase of the second division; paradesmose visible on two 

 nuclei; second division of parabasals and axostyles completed; both zooids 

 anterior. 



Fig. 24. The daughter zooids diverging to opposite poles in the as yet un- 

 divided protoplasm of the cyst. Note coincident divergence of nuclei and 

 neuromotor system in the absence of external free flagella. 



Fig. 25. Prophase of the second division with spireme forming in upper two 

 nuclei; one parabasal detached from its mate. 



Fig. 26. Prophase of second division with chromosomes doubled in each 

 nucleus, but in pairs, either in the early phase side by side, or in the later one, 

 swinging into an end-to-end relation. 



Fig. 27. Second division, two enlarged nuclei in telophase. Note heavy 

 parabasals. 



Fig. 28. Second mitosis; division nearly completed. One nucleus still in 

 prophase with doubled chromosomes, the other three nuclei having completed 

 their division. Note variation in size of nuclei, anterior location of all nuclei, 

 and lagging of division in the neuromotor system behind that of the nuclei. 



Fig. 29. Second division of nuclei completed. Division of nuclei and neuro- 

 motor systems (axostyles and parabasals) synchronous. 



Fig. 30. Large asymmetrical cyst with third division in progress showing 

 the nuclei widely divergent in size. Two zooids with larger nuclei, at opposite 

 poles of the cyst. 



Fig. 31. Third division partly completed, with twelve nuclei but only a 

 single pair of axostyles. 



[234] 



