182 



H. M. WOODCOCK. 



kinetic constituents, which are practically separate and inde- 

 pendent, at any rate, during the trjpanosome phase; and 

 (b) in the looseness of the union between the male and female 

 elements. The fertilisation spindle or definitive nucleus is to 

 be regarded as representing the trophic portion, and it will 

 be convenient, therefore, to distinguish it as the tropho- 

 nucleus. When reconstituted and in the resting condition 

 this body possesses, as the normal number, eight distinct 



Fig. 7. — Ookinete of Trypanomovpha (or Halteridium) 

 noctuse (Celli and San Felice). The fertilisation spindle has not 

 yet become rounded ofE (see text). Jc, h' = kinetonuclear elements 

 of the male and female gametes, not yet united ; v = vacuole ; 

 r.n. = residual nuclei and pigment grains. (After Schaudinn.) 



chromatic aggregations or chromosomes (fig. 8 a, t.chr.)} 

 Close to either end of the spindle is another chromatic body 

 (fig. 7, h, k'). These two masses also come from the micro- 

 and megagamete respectively. They proceed to fuse, and 

 the resulting body, which may be termed the kinetonucleus, 

 passes into the now rounded trophonucleus, where it takes up 

 a central position. The kinetonucleus also possesses eight 

 peripherally situated chromosomes (fig. 8 a, ^•.c/ir.), embedded 

 in a plastinoid matrix; near its centre lies a centrosomic 

 granule (c), surrounded by a clear zone. As the name 



' Strictly speaking, these ought perhaps to be regarded as balf-chromo* 

 somes. 



