B66 University of California PuhJications. [Zoology 



The results, in the main, of the motor reactions in cut pieces 

 are the same for the two parts as for whole individuals, showing 

 first, a backward movement, a turning- toward the right away 

 from the oral side and then a movement forward. The means by 

 wliich the reaction is accomplished ditifer in the two ends. 



20. 



Fig. 20. — Piece B exhibited the bending of the body during the backwMiil 

 movement of the motor reaction. 



GENEEAL SUMMARY. 



The movements of Condylostoma patens are directly depend- 

 ent on the shape of the body. Normally the animal moves in a 

 circle to the left when gliding. This is caused by the bend of 

 the posterior end of the body toward the left. 



The spiral swimming is the result of the curvature of the body 

 and not "wholly dependent on the oblique position of the cilia. 



The motor reaction is the same as for other Protozoa. It 

 consists of a backward movement, a turning toward a structur- 

 ally defined side and then a movement forward. 



The motor reaction is of the same type in cut pieces as in 

 whole individuals but modified by the form of the pieces. 



Zoological Laboratory, University of California, 

 January 14, 1907. 



