455 



across to its apropriate position in relation to the shifted blepharo- 

 plastic granule and is then cut off by a simple constriction (see figures 

 3—5). 



The Trophonucleus: — The division of the trophonucleus is rather 

 peculiar, especially in its early stages. It would appear that the karyo- 

 some of the active individual does not contain a very large proportion 

 of chromatin since in animal which have been stained with haemalum 



Fig. 5. 

 Fig. 4. , 



/ -. ; Fig. 6. 



*** '"-•-=*&, ;- 



f-Z 



\ 





Figure 4. Later showing end of kinetonucleus division, the flagellum attached to 



one blepharoplast has already split. 



Figure 5. Later stage both blepharoplasts have two flagella. 



Figure 6. Later stage only one flagellum could be traced in one of the daughter in- 

 dividuals, the other one probably wrapped around the body. 



or lightly stained with iron haematoxylin and then afterwards stained 

 with eosin it is quite easy to get forms in which the granules of the 

 kinetonucleus are stained as chromatin while the karyosome has taken 

 up the eosin. It would appear in division that the karyosome disappears 

 and that the chromatin contained in the karyosome and the extrakaryo- 

 some chromatin condense at one pole of the nucleus, giving rise to the 



Fig;. 7. Fig". 8. 



so 



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Figure 7. Last stage of division, the connecting zone between the two individuals is 



occupied by large vacuoles. 



Figure 8. The cyst. 



very characteristic appearances shown in figure 2. The band of chro- 

 matin thus formed becomes stretched out the nuclear membrane at the 

 same time disappears giving rise to such appearances as are shown in 

 figures 5 and 6. During the later stages of these processes the body of 

 the animal becomes rather drawn out and the vacuolar area appears to 

 become concentrated in the zone which connects the two daughter in- 

 dividuals this evidently splits across. The last stages of division when 



