G O ■ R G O N I A. 71 



cc and arrive at the height of about a line and a half (the 

 " eighth part of an inch) it widens at bottom and at. the 

 cc top, and grows narrower in the middle, affuming the 

 ££ proper confidence and hardnefs of coral ; and as this 

 cc grows, the polypi are multiplied, and new branches 

 C£ of coral are formed." So that we fee, as ioon as the 

 Polype from the eggdate extends itfelf, and draws in. 

 nourishment, its hard part, or bone, appears even before 

 it is one-eighth of an inch high. 



The dems then of the-fe animals, when they firft grow 

 up, are always full of cells with their polypes, even down 

 to the bafe ; but as they advance towards their full fize, 

 indead of fo many polype mouths (in fome particular fpe- 

 cies) we find the fleiny part of the trunk and bafe com- 

 pofed of organs full of parallel connected tubes ; thefe 

 fpread themfelves downwards, over rocks or Shells in va- 

 rious directions, drawing nourishment from the polype 

 mouths above, to fecure the animal more firmly in its da- 

 tion ; for from under thefe tubes, as in the dem, pro- 

 ceeds and is formed a hard or bony part, which adheres ; 

 mod drongly to the rocks, &c. and enables the animal to 

 refid the violence of the waves. As the tubes on the bafe 

 confid of the fame flefhy organical parts with thofe of 

 the dem and branches, they mud undoubtedly receive 

 their fupply of animal juices from the nourifhment drawn 

 in by the polype mouths above them: this will appear 

 clear to us, when we confider they are real Polypes, only 

 with the addition of a bony part : and it is well known 

 in experiments made on the Hydra, or frefh- water Polype, 

 when it has many heads, that if one of them only is fed, 

 all the red will receive nourifhment, and grow ; that is, 

 new heads will arife from the fides, and there will be a 

 circulation of vital juices through the whole to the bafe, 

 n which 



