POLYPES. 
57 
Gervais has shewn that the component grannies 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 papilla; 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. 
