THE FRESH- WATER HYDRA. 



81 



dka never allows its fingers to swallow it, as the amoeba 

 is swallowed by its feet. When it is disturbed or 

 frightened it seems to swallow its fingers, or puts them 

 all into its mouth like a sulky child. It is a good deal 



Fig. 80. 



Hydra pushing out its Fingers. 



higher up in the world than the blood-cell, or am<eba, 

 for you remember the amceba had to eat with its feet. 

 Then, too, the hydra has a more aristocratic walk than 

 the amceba. You can see it plant its foot firmly against 

 the glass, then proudly bow its back and draw the rest 

 of its body up to the foot in the form of a loop, like 

 the " looping caterpillar " (Fig. 81). To be sure, it goes 

 backward, but it is a great improvement on the crawl- 

 ing and creeping of the amceba; besides, it is a very 

 good swimmer. You may often see it lift up its foot 



