58 THE LONG-ARMED HYDRA. 



sucker up to the mouth as before, and thus it moves 

 on in slow but certain succession ; for a journey of 

 a few inches, in this way, occupies several hours. 

 A more expeditious progress is therefore effected 

 by a series of somersets. Adhering by the sucker, 

 the latter is detached, but, instead of being brought 

 to the mouth, it is thrown beyond it, as far as pos- 

 sible, describing a semicircle ; and a similar move- 

 ment is then made by the head. 



Nor are these its only means of locomotion. In 

 the water, the hydra moves with great rapidity. 

 Suspended with its head downwards, its sucker acts 

 as a float on the surface, and it is consequently 

 drifted with the current of the stream. Wafted 

 along by the breeze, or grasping objects within the 

 reach of its arms, it propels itself onwards ; and 

 then at its pleasure it holds firmly by a stem or a 

 leaf, its little harbour after a voyage, and moors 

 itself into a state of quietude and rest. 



The manner in which these creatures obtain food 

 is seen most clearly by watching the movements 

 of the long-armed hydra. If a piece of the stem, 

 or some of the leaves to which these polyps are 

 attached be put into a clear phial, filled with water, 

 and placed in a window, they will soon be observed 

 to extend their arms in quest of prey. If a small 

 worm be then dropped into the water, it will 

 instantly throw itself into violent contortions, as if 

 conscious of danger, while its enemies will be 

 roused into full activity. A hydra will soon be 



