132 



THE SEA SHORE 



these must therefore be provided, as we have Been they are, with a 

 means by which they may derive nourishment through the agency 

 of the feeding polypites. 



When the eggs are liberated from what we may call the repro- 

 ductive members, they are carried away by the currents or tides, 



FIG. 82. Tubularia indivisa 



FIG. 83. THE BOTTLE BKUSH 

 (Thuiaria thuja) 



and soon develop into little larvce which are very unlike the parent, 

 since they are covered with minute vibratile cilia by means of 

 which they can swim freely. This they do for a period, and then 

 settle down, lose their cilia, become stalked, and thus constitute 

 the foundation of a new colony. A tubular stalk grows upward 

 from its root, new members are added as outgrowths or buds 



