POLYPES. 



57 



Gervais has shewn that the component granules of the 

 body are of diverse forms, and, in all probability, sustain 

 different relations to the general economy. The whole 

 body consists of a sac, with thin dilatable walls, enclosing 

 a capacious cavity, which forms the stomach : the granules 

 which border this cavity are conical papillae projecting 

 into the stomach, and are supposed to have a digestive 

 function ; the exterior series are lengthened, and consti- 

 tute an integument, while some of the intermediate ones 

 are arranged in bands, which are, with little doubt, pre- 

 sumed to be muscular. The muscular bands in the ten- 

 tacles are still more distinct, running in four series, which 

 pass diagonally to and fro from side to side, forming 

 lozenge-shaped spaces by mutual intersection. 



