B 



C.TCIC 



FIG. 71. Paramoecium caudal um. 



A, the living animal from the ventral aspect, showing the covering of cilia, the 

 buccal groove (to the right) ending posteriorly in the mouth (mth) and gullet 

 (gul) ; several food vacuoles (/. vac) and the two contractile vacuoles (c. vac). 

 (x 300.) 



263 



