272 



SUBKINGDOM CCELENTEKATA. 



they attach themselves at will to any solid object Their 

 mouth is surrounded by hollow tentacles, by which they 



seize their food, and 

 2 t , quickly benumb it. Cut 



into pieces, each part 



3\ / *^/ quickly grows into s 



perfect animal. 



Fig. ItSU. 



The Campanularia 

 are allied to the Sertula- 



Fresh water Hydras. 1. Stem of plant, ; 2. Hydra "a. From their bell- 

 attached and budding ; 3. Partly expanded; shaped CUpS there drop 

 4 Fully expanded ; 5. Free and progressing. ^ ^ maturity free 



Medusoids. After leading an independent and locomotive 



existence for a time, these produce ova and sperm -cells, 



the resulting embryos of which fix themselves 



and develop into plant-like colonies, from 



which fresh medusoids may bud. The Med- 



usoid little resembles the plant-like Zoophyte 



from which it thus springs. It sails through 



the water by the contraction of its bell, the 



tentacles hanging like a fringe below, and the four radiating 



canals leading to its central stomach. 



Medusoid. 



