154 



THE ANIMAl, KINGDOM, 



in the water. These animals arc sometimes called 

 " Medusae," as it is supposed their stinging appendages 

 are like the snakes on the head of Medusa,* and they arc 

 also termed Jelly-fishes. 



The class Polypifera, or Coral-forming animals, 

 represents those generally known as Zoophytes,! and 

 which are also termed Anthozoa.t The class seems to 

 be connected with the last-mentioned by the Hydrozoa, 

 or Hydroid Zoophytes. The little animal representing 

 this class, the Fresh -water Hydra (Fig. 107), has 



been described in "Our 

 Bodies," in relation to its 

 simple mode of digestion, 

 consisting as it does of a 

 mere tube, around the 

 end of which a series of 

 thread-like tentacles are 

 arrayed ; and fixing it- 

 self to a twig, or straw, 

 or leaf, by means of its 

 sucker, it throws these 

 out, as a Brazilian horse- 

 man throws out his lasso. 

 Not only may the animal 

 be turned inside out 

 without injuring its digestive powers, but it may be cut 

 into any number of pieces, and each will become a perfect 

 Hydra One of this tribe is called the Campanularia, || 

 and consists of a number of branches like those of a plant, 



* Medusa, in mythology, a beautiful female, whose flowing hair was 

 changed into snakes by Minerva. 



t Zoon, an animal ; phyton, a plant. 



t AntJios, a flower ; zoon, an animal. 



Hydra, a monster mentioned in fabled story, which had the power of 

 forming new heads as fast as others were cut off. 



H Campanula, a little bell. 



Fig. 107. 



