EXPLANATION OF PLATES 



All the figures of Naegleria gruheri (Schardiuger) were drawn with a camera 

 lueida. Most of the material drawn was iixed with acetic-sublimate-alcohol and 

 stained by Dobell's method, except the following; plate 20, figure 40, plate 21, 

 figures 79 and 83, plate 22, figure ti2, haematoxylin; plate 20, figure 49, plate 22, 

 figures 93 and 94, Alexeieflf's triple stain. X 2000. 



PLATE 18 



Fig. 1. Prophase with elongated nucleus and karyosome, the latter vacuolated. 



Fig. 2. Vacuolated, dumb-bell shaped karyosome with spindle fibers form- 

 ing. Fibers at the end show, others are covered by the karyosome. 



Fig. 3. Same as fig. 2. Spindle developed farther. 



Fig. 4. Early prophase. Karyosome vacuolated. Peripheral chromatin more 

 evident. 



Fig. 5. Projihase with karyosome dumb-bell slui|ied. Perijilieral chromatin 

 still at nuclear membrane. 



Fig. 6. Anaphase. Two polar caps visible. Chromosomes fused early. 



Fig. 7. Spindle of late prophase with definite, deeply staining chromosomes. 



Fig. 8. Late anaphase. Nuclear membrane closing around daughter nuclei. 



Fig. 9. Late prophase showing polar caps, granular chromatic polar masses, 

 eight spindle fibers with lightly stained chromosomes, and central spindle. 



Fig. 10. Early anaphase. One distinct polar cap, all chromatin granular, 

 central spindle visible at side. 



Fig. 11. Very early anaphase. Polar caps not visible, chromosomes separating. 



Fig. 12. Late telophase. Daughter amoebas almost separated. 



Pig. 13. Nuclear membrane pinched in, chromosomes sejiarate, no |iolar caps. 

 Food vacuole in cytojdasm. 



Fig. 14. Late anaphase. Further elongation and beginning of chromosome 

 fusion. 



Fig. 1.5. Telophase. Pseudopodia put out to jiuU daughter amoebas apart. 

 Extrusion of peripheral chromatin net. Two chromatic masses fusing around 

 centrodesmose of new nucleus of upper amoeba. 



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