56 STUDIES IN ANIMAL LIFE. 



cant as so many stems of duckweed ; and, lest you 

 should be equally indifferent, I will at once inform 

 you that these creatures will interest you as much 

 as any that can be found in ponds, if you take the 

 trouble of studying them. They can be cut into 

 many pieces, and each piece will grow into a per- 

 fect Polype ; they may be pricked or irritated, and 

 the irritated spot will bud a young Polype, as a 

 plant buds; they may be turned inside out, and 

 their skin will become a stomach, their stomach a 

 skin. They have acute sensibility to light (toward 

 which they always move), and to the slightest touch ; 

 yet not a trace of a nervous tissue is to be found in 

 them. They have powers of motion and locomo- 

 tion, yet their muscles are simply a network of 

 large contractile cells. If the water in which they 

 are kept be not very pure, they will be found in- 

 fested with parasites ; and quite recently I have no- 

 ticed an animal or vegetal parasite I know not 

 which forming an elegant sort of fringe to the 

 tentacles ; clusters of skittle-shaped bodies, too en- 

 tirely transparent for any structure whatever to be 

 made out, in active agitation, like leaves fluttering 

 on a twig. Some day or other we may have occa- 

 sion to treat of the Polypes in detail, and to narrate 

 the amusing story of their discovery ; but what has 

 already been said will serve to sharpen your atten- 

 tion, and awaken some curiosity in them. 



Again and again the net sweeps among the weed 

 or dredges the bottom of the pond, bringing up mud, 



