470 GENERAL BIOLOGY 



peristome, will, for a time, merely withdraw its body by 

 direct contraction. If at each extension the stimulus be 

 repeated, the stentor will swing its body first to one side 

 and then to the other. If this be unavailing and the stimu- 

 lus be continued, the animal will free itself from its support, 



ARISTOTLE 



(384-322 B. C.) 



Naturalist and Philosopher. 



and swim away. This method of avoidance is, however, 

 quite automatic. If the stentor be again stimulated when 

 it has attached itself in a new place it will go again through 

 the entire series of varying responses under the same stimu- 

 lation. It learns nothing by the repetition. 



