41 



FIQ. 6. The Nagana parasite ( Trypanosoma brucei), and four blood 



corpuscles. (Highly magnified.) 

 From a photo-micrograph by J. A. Ballantyne. 

 T. Trophonucleus. 

 K. Kinetonucleus. 

 V. Vacuole. 

 F. Flagellum. 

 U. Undulating membrane. 



How do Trypanosomes move ? 



Movement may be swift and dashing, wriggling, or 

 sluggish (as in Trypanosoma brucei). In active movement 

 the free portion of the flagellum rapidly propels the try- 

 panosome and is aided by the vibratile undulating mem- 

 brane, which exhibits wavy motion. Slow slithering 

 movement is by flexion and " euglenoid " contraction 

 of the body. 



