LESSON 30.] NUTRITION IN POLYPI. 105 



namely, by cutting them in pieces, when each portion will become a 

 perfect animal. 



518. We have referred to the Marine Polypi ; do our readers 

 chance to know that the red coral of Commerce, which forms such a 

 pretty ornament for the necks of children, is composed of Carbonate 

 of lime, and once formed the internal skeleton of a family of Polypes, 

 by whom it was manufactured ? 



519. The Order of Polypes, to which Corallium rubrum (red 

 coral) belongs, possess eight short, broad, leaflike tentacles around 

 the mouth, and in this species they are white. The deeply red- 

 colored skeleton is, as has been said, internal ; it is covered by a red 

 flesh, of paler color than the skeleton, and this is everywhere exca- 

 vated into little cavities, for the reception of the individual Polypes. 

 In this order the young continue to form a part of one common 

 family, which may number several hundred individual members ; 

 they bear the same relation to each other, and the group with which 

 they are connected, that the leaves bear to a tree. 



520. The excess of nutriment FIG. iso. 

 due to the combined nutrition of so 



many members, goes to extend the 

 common mass ; to make new bone, 

 cover it with new flesh, and to place 

 in its cells a new family of Polypes. 

 An illustration of this species is 



FIG. 179. 



Bed coral, polypes in situ. Polype of Corallium rubrum. 



given (Fig. 179), in which the bone (a) is shown, covered with the 

 flesh (6), and the polypes, with the tentacula displayed (c), emerging 

 from the cells. 



521. To show the general structure, and especially the alimentary 

 canal of this polype, a. magnified figure is given (Fig. 180). The ex- 



