I 4 6 RAMBLES AND REVERIES. 



others are of uncertain affinities (Manual of 

 Zoology, p. 189). 



It is clear, therefore, that the term Coral has 

 no definite zoological signification, and that as geo- 

 logically used it indicates in general most of the 

 organisms now included in Zoantkaria scleroder- 

 mata (Madrepores), Rugosa, and Alcyonaria. 



The soft parts of the polype which secretes the 

 hard " corallum " do not differ essentially from the 

 sea-anemone. The stony corals of the geologist 

 were secreted by a colony of such polypes, all of 

 which, however, were united by the common flesh 

 (coenosarc). The corallum consists of a number of 

 " corallites," or individual skeletons, these having a 

 common calcareous basis. 



It is possible to study the habits of the living 

 coral polype, for on our warm southern coasts several 

 species may be met with. If one of the simple 

 corals or madrepores, say a Caryophyllia of the 

 Devonshire coast, be placed in an aquarium, it will 

 probably survive. When examined, it will be seen 

 to possess numerous tentacles, in circular sets. 

 The mouth is reddish generally, and has bars of 

 white. The large plates or septa seem to radiate 

 like the spokes of a wheel, dividing the inside basin 

 into chambers. The creature obtains its food by 

 means of cilia which waft the water to the mouth, 

 or by direct capture of its prey with the tentacles. 

 The lime which may form part of the food thus 

 captured goes to construct the "corallite" or 

 skeleton. 



The architects of coral rocks are polypes of many 



