THE H^MOFLAGELLATES. 185 



but denser, richer in plastin, and more deeply staining than 

 the other. 



In this manner, therefore, two distinct nuclear bodies are 

 formed, of different size and structure. The larger one, 

 lying nearer the middle of the body, which rapidly recon- 

 stitutes itself (fig. 8 d), is the trophonucleus; its chromo- 

 somes have become long, winding threads. The eight 

 chromosomes of the other, the kinetonucleus, are only to be 

 made out distinctly in maceration preparations. Situated 

 near the middle of each nucleus is a small ceutrosomic grain. 

 These two intra-nuclear centrosomes are connected by a fine 

 achromatic thread, which represents the remains of the axial 

 spindle. 



While the trophonucleus now enters upon a resting phase, 

 the kinetonucleus proceeds to form the characteristic loco- 

 motor apparatus of the Trypanosome. It passes forward 

 slightly, and takes up a position at the periphery of the 

 endoplasm, lying, indeed, against the limiting ectoplasm.-^ 

 Its centrosome divides again in a dumb-bell-like manner,- 

 and forms another axial spindle (e, a.sr) at right angles, as 

 before, to the length of the organism. The chromatin be- 

 comes aggregated round either end, again in a slightly hetero- 

 polar fashion, the dorsal half being somewhat the smaller. 

 There are now two daughter-kinetonuclei, the one on the 

 right being quite in the ectoplasm ; they also remain con- 

 nected together by the drawn-out central spindle, which, as 

 before, joins the two centrosomes. The peripheral daughter- 

 nucleus forms yet another spindle (fig. 8 p, a.s.^), whose axis 

 is now, however, longitudinal. This assumes large propor- 

 tions, and spreads forward to the anterior end of the body 



^ Schaudlnn thus mentions the existence of a definite ectoplasmic layer 

 hut does not describe it, nor do his figures indicate it (apart from the 

 undulating-membrane) at all clearly' ; see, however, below, p. 209, et seq. 



- The behaviour of this organella strongly recalls that of the " nucleolo- 

 centrosome " of Euglena, during division, and also that of the karyo- 

 some of many Coccidia in schizogony; quite possibly, it should be con- 

 sidered in the double light of a "karyo-centrosome." 



