HYDRA. 



75 



us, it is rather a pretty object ; but if one casts 

 about for a similitude it is rather difficult to find 

 one. The knotted cat-o'-nine-tails supplies a not 

 inapt comparison, both as to form and function. 

 A handle with knotted cord or thongs at one end, 



FIG. 12. Hydra fusca on anacharis. 

 A. Natural size expanded. B. Natural size contracted. 



when wielded with a strong arm and falling on the 

 back of a criminal, is said to sting ; and here is an 

 animal just of this form : a hollow or sub-cylin- 

 drical body, with from five to ten slender serrated 

 or knotted-like arms springing from its head, 

 each armed with poisonous stinging organs, which 

 spring out with marvellous velocity at the moment 

 of impact with~its prey killing some at once and 



