224 
THE OCEAN WOIiLl). 
organs of digestion also present arrangements peculiar to themselves ; 
the mouth is placed on the lower part of the body, and is pierced G 
the extremity of a trumpet-like tube, hanging sometimes like ft® 
tongue of a bell. The walls of the stomach, again, are furnished will' 
a multitude of appendages, which have their origin in the cavity ^ 
the organ, and which are very elastic. The stomach, furnished with 
these vibratile cells, appears to secrete a juice whose function is t° 
attack the food and render it digestible. 
In some of the Medusadas the central month is absent altogether 
With the Rhizostoma, for instance, the stomachal reservoir has 
inferior orifice; it communicates latterly with the canals wb jC . 
descend through the thickness of the arms, and open at their extrefl * 1 
ties through a multitude of small mouths. These are the root-l^ 1 ' 
openings from which the animals derive their name of Rhizoston 13 ’ 
from the Greek words piCft. root, and aiofxa, mouth. 
The arms of the Rhizostoma are usually eight in number, the h ® 6 
