8 



PLANT-ANIMALS 



[CH. 



C. paradoxa possesses, in addition to cilia, occa- 

 sional, stouter, bristle-like structures which stick out 

 from its body, chiefly in the "tail' region (Fig. 16, 

 p. 84). These structures serve, when put in action 

 by the animal, to pin it down and thus enable it to 

 stop and stick in any position. 



Fig. 2. Convoluta paradoxa (C) attached to sea-weeds 

 of the paradoxa zone. (Magnified eight times.) 



In both animals, the sides of the body are flexed 

 beneath the under surface, and together form a groove 

 which, in C. paradoxa, serves to fit the animal saddle- 

 wise to the fine sea-weeds over which it glides (Fig. 2). 

 This animal, in its general progress, appears almost 

 to flow over the substratum on which it is moving. 



