192 AGE OF CORAL REEFS. 



time we have no evidence of any change in 

 Species, but, on the contrary, the strongest proof 

 of the absolute permanence of those Species 

 whose past history we have been able to trace. 



Before leaving the subject of the Coral Reefs, 

 I would add a few words on the succession of the 

 different kinds of Polyp Corals on a Reef as com- 

 pared with their structural rank and also with 

 their succession in time, because we have here 

 another of those correspondences of thought, 

 those intellectual links in Creation, which give 

 such coherence and consistency to the whole, 

 and make it intelligible to man. 



The lowest in structure among the Polyps are 

 not Corals, but the single, soft-bodied Actinia. 

 They have no solid parts, and are independent 

 in their mode of existence, never forming com- 

 munities, like the higher members of the class. 

 It might at first seem strange that independence, 

 considered a sign of superiority in the higher 

 animals, should here be looked upon as a mark 

 of inferiority. But independence may mean 

 either simple isolation, or independence of ac- 

 tion ; and the life of a single Polyp is no more 

 independent in the sense of action than that of 

 a community of Polyps. It is simply hot con- 

 nected witli or related to the life of any others. 

 The mode of development of these animals tells 

 us something of the relative inferiority and su- 



