THE HAEMOFLAGELLATES 



223 



portion, which becomes thickened and then divides, one half break- 

 ing away as a new, short flagellum, whose further growth is basal 

 and centrifugal (Fig. 20, D). Schaudinn found, however, that in 



A. C 



FIG. 17. 

 Stages in binary longitudinal fission of T. brucii. (After Lav. and Mesn.) 



Trypanomorphi noctuae the whole of the flagellum, etc., is developed 

 quite independently from the daughter-kinetonucleus, and laid 

 down alongside and parallel with the old locomotor apparatus ; 

 moreover, Prowazek (I.e.) and also M'Neal (56) maintain that the 

 same is the case in T. lewisi. Nevertheless, in many cases it seems 

 hardly possible to doubt that there is actual splitting of the 

 flagellum ; where, for in- 

 stance, the two new flagella 

 of the proximal part of the 

 body appear to actually 

 join arid continue as one, 

 yet undivided flagellum 

 (as seen in Fig. 17, A 

 and B). Again, even 

 where a daughter-flagellum 

 is separate from the main 

 one, the course of the two 

 is often so exactly parallel 

 that their origin by longi- 

 tudinal fission is highly 

 probable. 



So far, we have not much knowledge with regard to the 

 cytological details of nuclear division. Prowazek has given a 

 description of the process in T. brucii. The kinetonucleus becomes 

 thickened and spindle -like (Fig. 18, A). Subsequently it becomes 



Flo. 18. 



Details in the nuclear division of T. brucii. 

 (After Prowazek.) 



