298 ELEMENTS OF COMPARATIVE ZOOLOGY* 



the base. Could food pass from the oesophagus into the 

 inter- and in tra- radial chambers ? Do you find any body- 

 cavity distinct from the digestive cavity ? Do you find any 

 opening to compare with a vent ? 



Along the free edges of the mesenteries are the coiled 

 mesenterial filaments. Do they present the same appear- 

 ance nearer the oral disc that they do farther down ? On 

 the sides of the septa near the mesenterial filaments are the 

 reproductive organs (not always plainly visible). 



