100 



THE VITAL FUNCTIONS. 



or disk, by which the animal adheres to rocks : 

 I is the section of the coriaceous integument, 

 showing its thickness : m is the central aperture 

 of the upper surface, which performs the office 

 of a mouth, leading to s, the stomach, of which 

 the lower orifice is open, and which is suspended 

 in the general cavity, by means of vertical par- 

 titions, of which the cut edges are seen below, 

 uniting at a central point, c, and passing between 

 the stomach and the integument. These mus- 

 cular partitions are coimected above with three 

 rows of tentacula, of which the points are seen 

 at T. The ovaries (o) are seen attached to the 

 partition ; and also the apertures in the lower 

 part of the stomach, by which they communicate 

 with its cavity. 



If we considered the medusa as having four sto- 

 machs, we might in like manner regard the Aste- 

 riaSy or star-fish, as having ten, or even a greater 

 number. The mouth of this radiated animal is 



at the centre of the under surface ; it leads into 

 a capacious bag, situated immediately above it, 



