358 



APPENDIX. 



which terminate at one end in a stiff, immotile, acutely- 

 pointed, flexible filament or spine-like process, and at the 

 opposite end are provided with a long flagellum, while 

 longitudinally attached a delicate undulating, fin-like 

 membrane can be traced, which starts from the base of 

 the posterior filament, and becomes directly continuous 

 with the flagellum (Fig. 133). 



With careful illumination the body is found to be 

 distinctly granular, with one or more highly-refractive 

 spherules. When the rapid movement is arrested the 

 undulating membrane is distinctly visible. The best 

 opportunity occurs for seeing this when the organism 



FIG. 134. MONADS IN RAT'S BLOOD, x 1200. 



, A monad threading its way among the blood-corpuscles ; b, another with 

 pendulum movement attached to a corpuscle ; c, angular forms ; d } encysted 

 forms; e and/, the same seen edgeways. 



comes to partial rest with its stiff filament against a 

 corpuscle, as if to obtain a point d'appui, while lashing 

 its flagellum in all directions (Fig. 134, ). At other 

 times, when the parasite has impinged with its posterior 

 extremity against a corpuscle, or the stiff filament is 

 apparently entangled in debris, the movements of the 

 organism give one the idea of its endeavouring to set 

 itself free. 



In the active state the thicker portion, or body, appears 



