48 CORALS AND CORAL ISLANDS. 



prominence on the side of the parent. The prominence en- 

 larges, a mouth opens, a circle, of tentacles grows out around 

 it, and increase continues till the young finally equals the 

 parent in size. Since in these species the young does not 

 separate from the parent, this budding produces a compound 

 group ; and the process often continues until in some instances 

 thousands, or hundreds of thousands, have proceeded from a 

 single germ, and the colony has increased to a large size, 

 sometimes many feet, or even yards, in breadth or height 

 Such is the species of Dendrophyllia represented in the fig- 

 ure on page 51, and the Madrepora figured on page 50 ; in 

 both of which, and in all such coral zoophytes, each stellate 

 cavity or prominence over the surface corresponds to a sepa- 

 rate one of the united polyps. 



The compound mass produced by budding — which con- 

 sists of the united polyps with the corallum as their united 

 secretion — was called in the Author's Report, a Zoophyte, it 

 being truly animal in nature, though under a plant- like form 

 through the plant-like process of budding. But the word to 

 many minds conveys the idea that the species is something 

 between a plant and an animal, which is totally false; and 

 besides, it is often used distinctively for the division of ani- 

 mals including the sponges. As a substitute the term Zoo- 

 thome may be employed, derived from the Greek £dov, ani- 

 mal, and d^nog, a heap — a term applicable also to compound 

 groups in other classes, as, for example, those of Rhizopods, 

 Bryozoans and Ascidians. The term zoophyte, where employ- 

 ed beyond, signifies a zoothome formed of united polyps, or a 

 polyp-zodilwme. The coral of the zoothome being the coral- 

 lum, that of each polyp in the compound corallum may be 

 called a corallet — the term calicle, formerly used by the 

 author for the same, being now restricted to the polyp-cell. 



