124 



MANUAL OF ZOOLOGY 



SECT. 



The almost infinite variety in form of the compound 

 corals is due, in the main, to the various methods of bud- 

 ding. According to the mode of budding, massive corals 

 are produced in. which the corallites are in close contact 

 with one another, as in Astrc&a (Fig. 59) ; or tree-like forms, 



FIG. 60. A, Dendrophyllia nigrescans ; B, Madrepora aspera. co. corallites 

 cs. cuenosarc ; p. polypes. (After Dana.) 



such as Dendrophyllia (Fig. 60, A\ in which a common 

 calcareous stem, the coenenchyma, is formed by calcification 

 of the coenosarc, and gives origin to the individual 

 corallites. It is by this last named method, the coenosarc 

 attaining great dimensions, and the individual corallites 



