606 Eadiata. 



unite and form one animal, though each section should 

 belong to a different species. The head of one species 

 may be engrafted on the body of another. When one 

 Polyp is introduced by the tail into another's body, the 

 two heads unite and form one individual. Pursuing 

 these strange operations, M. Trembley gave scope to his 

 fancy by repeatedly splitting the head and part of the 

 body ; he thus formed hydras more complicated than ever 

 struck the imagination of the most romantic fabulist. 



Though so difficult to destroy by division, all the 

 Polyps, even those which form the corals, may be easily 

 killed by depriving them of moisture, when they soon 

 shrivel up, and the tissue of their skins is completely 

 destroyed. 



OF these Fresh-water Polypi, only a few kinds are 

 known, but the sea nourishes a multitude of species 

 which closely resemble the Hydras in their structure, 

 from hence called Hydroid Polyps by Cuvier and many 

 other naturalists. Most of these are compound creatures, 

 of the kind shown in the above engraving, of which 

 many species may be found on all our shores. A horny 

 tube runs branching over the surface of a seaweed, or 



