240 H. W. WOODCOCK. 



form, and then repeated division of the nuclei (both kinds) 

 and flagellum goes on, each daughter-kinetonucleus remaining 

 in contiguity to the corresponding trophonucleus, and all 

 taking up a position of uniform distribution near the margin 

 of the cytoplasm (fig. 28 a — c). The cytoplasm next becomes 

 lobulated peripherally, and gradually segregates around the 

 nuclei, forming as many little, radially-arranged daughter- 

 Trypanosomes as there are nuclear groups (d).^ This method 

 of multiple division offers, it will be seen, considerable analogy 

 to the schizogony of Hgemosporidia, and the latter is probably 

 to be regarded as a modification of it, adapted to an intra- 

 cellular and gregariniform stage. 



These small Trypanosomas so formed (e) differ from the 

 typical adults by their stumpy, pyriform shape, the position 

 of the kinetonucleus near the flagellar end of the body, and 

 the absence, during the first part of their youth, of an undu- 

 lating membrane. The parasites have at this period, it is to 

 be noticed, a very Herpetomonas-like facies, the import- 

 ance of which is discussed below (p. 276) . These young indivi- 

 duals of T. lewisi can themselves multiply by equal binary 

 fission (fig. 28 r), and give rise to little fusiform Trypanosomes. 

 With growth the latter gradually assume the adult appearance, 

 by the progression of the kinetonucleus past the trophonucleus, 

 almost to the other end of the body, and the concurrent 

 development of an undulating membrane as the extended 

 flagellum takes up its regular superficially-attached position. 



Wasielewsky and Senn (1. c.) also describe and figure 

 multiple segmentation in this same parasite ; again Kabiuo- 

 witsch and Kempner, in a recent paper (90), mention that 

 they have occasionally observed appearances and groupings 

 of Nagana and Dourine parasites (T. brucii and T. equi- 

 perdum) which strongly suggest that these also possess, in 

 addition to the usual method of equal binary fission, a 

 similar modification. Apart from these instances, however, 



' A multiplication-rosette is readily distinguislied from a t^'pical agglo- 

 meration-cluster by the dilTerent shape of the individuals, and the different 

 position of the kinetonucleus (cf. fig. 20 b). 



