Unicellular^ Microscopic Animals 351 



short, tubelike gullet or cytopharynx. The side of the animal with the 

 oral groove is known as the oral or ventral side; the opposite, as aboral 

 or dorsal. The cilia within the oral groove and gullet propel certain 

 foods toward the food vacuole. Foods consist principally of bacteria and 

 other small protozoa. Numerous food vacuoles (droplets of water with 





Fig. 164. — Paramecium showing spiral locomotion. 1 , 2, 3, 4, 1 show successive 

 positions occupied. Dotted areas show currents of water drawn from the front. 

 (From Jennings: Behavior of the Lower Organisms, published by the Columbia 

 University Press.) 



