HYDRA AND CCELENTERATES IN GENERAL 



I2Q 



is to bring the animal into a new part of its surroundings, where 

 more food may be present (Fig. 59). These movements finally 

 cease, and the animal's position is changed by locomotion. 



FIG. 60. Hydra moving like a measuring worm. (From Jennings aftei 



Wagner.) 



LOCOMOTION. Movement from place to place is effected in 

 one of three ways. In most cases the animal bends over (Fig. 

 60, i) and attaches itself to the substratum by its tentacles 

 (2), probably with the aid of pseudopodia thrust out by the ecto- 

 derm cells. The basal disk is then released and the animal con- 



