234 



H. M. WOODCOCK. 



at any rate/ possesses another method in addition, namely, 

 rosette-like segmentation, which is easily derivable from 

 the former. Longitudinal fission in general follows, in its 

 main outlines, the process above described in the case of 

 Trypanomorpha nocture; the chief differences to be 

 observed are slight variations in mode and order of procedure. 

 Full-grown Trypanosomes about to divide are, as a rule, 

 rather broader than the ordinary adults; in T. lewisi, this 

 increase in size may be very marked, the parasites being not 



Fig. 23. — Stages in binary longitudinal fission of T. brucii. 

 (After Lav. and Mesn.) 



only much wider, but also longer (fig. 27 b). The kiueto- 

 nucleus is frequently the first to divide (fig. 23 a), but some- 

 times either the kineto- or the tropho-nucleus may do so 

 indifferently; whichever leads the way, the other very soon 

 follows suit (b). 



The duplication of the flagellum always begins at its 

 proximal end, which is in relation with the kinetonucleus. 

 Until recently the process has always been considered as an 

 actual longitudinal splitting of theflagellum, following upon the 

 separation of the two daughter-kinetonuclei. The splitting 



' See below, p. 210, for other possible instances. 



