22 SOME MINUTE ANIMAL PARASITES 



end is the anterior end, but the organism can move 

 with either end forwardly directed. The posterior 

 end is much blunter than the anterior, and is relatively 

 passive. Within the body are two nuclei, a large one 

 (Fig. 4, n.), usually oval, and a somewhat more deeply 

 staining smaller nucleus, termed a blepharoplast 

 by the majority of scientific workers (Fig. 4, bl.). 

 Some workers, however, consider that this second 

 nuclear body must have some controlling influence 

 over locomotion, because the flagellum arises in its 

 vicinity, and so call it a kinetic nucleus. As 

 further proof of the existence of this function is 

 needed, it can only be regarded as an interesting 

 suggestion or idea, especially as some trypanosomes 

 are known in which a blepharoplast is absent. The 

 blepharoplast is much smaller than the nucleus, and 

 extends usually transversely across the body of the 

 parasite, and is nearer the posterior end than the 

 nucleus. The blepharoplast, as a rule, shows no 

 internal differentiation until the period for multipli- 

 cation by division occurs, and then it may pre- 

 sent various f9rms, which will be described when 

 dealing with division. The general body substance 

 of the living trypanosome consists of a finely granular 

 protoplasm, in which larger granules may be em- 

 bedded. 



The trypanosomes live at first in the blood of 

 their human victim, but some very soon pass from 

 the blood into the lymphatic glands, and thence later 

 make their way into the fluid in the tiny canal that 

 occupies the centre of the spinal cord, and that 

 expands into larger chambers within the brain. The 



