410 



RADIATA. 



what appear to be beautiful starry flowers, but are 

 really Polypes with eight fringed tentacles, some- 

 times expanded, and sometimes contracted into little 

 cells in the flesh. The stem is solid, not perforated, 

 but furrowed down the surface : it is susceptible of 

 a high polish. It is affixed by a broad base to the 

 surface of rocks, in the Mediterranean, where it is the 

 subject of a lucrative fishery. It grows with some 

 rapidity, as places that have been exhausted are 

 found by the coral-fishers to be in a few years quite 

 replenished again. There are, however, local laws, 

 which prohibit the too frequent disturbance of the 

 beds. 



But the most important of these animals is found 

 in a group which is commonly known by the name 

 of Madrepore, whose stony centres, seen in every 

 cabinet, form thin perpendicular plates, which run 

 to a centre, or terminate in waving lines, and by 

 their thinness and close position remind us of the 

 gills of a mushroom. At the hollows in the centres, 

 where these leaves converge, were found, when alive, 

 the Polypes by which the mass was secreted. Feeble, 

 and apparently insignificant as these animals are, 

 they have a mighty work assigned to them by God, 

 and perform an important office in the economy of 

 the earth. Vast reefs of solid rock which oppose an 

 unyielding breast to the waves of the broad Pacific, 

 and even large clusters of islands, inhabited by 

 thousands of now civilized and Christian men, have 

 been raised by the united efforts of millions of 



