Ill 



COELENTERA TA 



43 



Though usually stationary, a Sea-anemone can move slowly 

 over the rocks, gliding along on its broad base. Certain 

 anemones will occasionally detach their bases from the rock, 

 and drag themselves along by their tentacles in an inverted 



t 



FIG. 20. One-half of the Body of a Sea-anemone. (Diagrammatic.) 



t, Tentacle ; oe, gullet or oesophagus ; m, one mesentery or septum seen in surface 

 view ; the six others shown are seen from their inner edge.s ; e, reproductive cells 

 on the free edge at the base of a septum ; c, cavity between two septa. 



position ; this is said to have been observed frequently in 



the case of anemones kept in aquaria. 



One of the most striking differences in internal 

 s k ruc k ure between the Sea-anemone and the Hydra 

 is the position of the mouth-tube. In Hydra this 



projects outwardly as a short cone ; in the Anemone it is 



