FLAGELLATA 



237 



teeth and in inflamed gums; it may have some effect in con- 

 tinuing a gingivitis. 



FLAGELLATA 



The flagellata derive their name from the fact that all are pos- 

 sessed, at some time in their existence, of flagella, which are not 

 only organs of locomotion, but serve to apprehend food. 



The principal members of this class of interest from a patho- 

 logical viewpoint, are the trypanosomes. Trypanosoma gam- 



FIG. 74. Trypanosome in rats' blood. (Williams.) 



biense, transmitted by the tsetse-fly Glossina palpalis, pathogenic 

 for man (see page 239). The Trypanosoma brucei, which causes 

 the tsetse-fly disease (nagana) in horses and cattle, is transmitted 

 to cattle by the bite of the tsetse-fly, Glossina morsitans. It can 

 be grown on blood agar (Novy). 



Trypanosoma evansi causes surra, a disease of horses in Central 

 Asia transmitted by a fly of the genus Stomoxys. 



