470 BADIATA : POLYPI. 



anemones or Actiniae have a row of eyes jnst outside of 

 the tentacles ; and, according to Dana, these eyes have 

 crystalline lenses and an optic nerve. It is not probable, 

 however, that these eyes enable the animal to see objects 

 as do those of higher animals. 



Most kinds of polyps are attached to the rocks, shells, 

 or other bodies beneath the waves. Some live singly ; 

 others in small clusters ; and others in communities whose 

 numbers are almost beyond calculation. 



Polyps increase by means of eggs; by budding and 

 branching in a manner much like that of trees and shrubs ; 



FIG. 707. 



Spontaneous fission or division in Pulyps one polyp becoming two. 



and by division of one animal into two or more. Thus 

 the largest communities arise from a single animal. 



The eggs are formed on the radiating partitions, and 

 pass out through the mouth into the water. 



When first hatched the young are not like the parent, 

 but are little oval bodies which move freely about by 

 means of fringe-like appendages called vilratile cilia. 

 At length each of these little bodies becomes attached to 

 a rock, or shell, or sea-weed, and soon assumes the form 

 of the parent. If it be a kind which buds, there soon 

 grow from its sides or base others like itself ; and from 

 these, in turn, bud other polyps of the same kind ; and 



