232 PORIFERA 



6. The Nervous System. It has no differentiated nerve cells. 



(1) Has it irritability? How shown? Use? 



(2) Automatic actions. Name those of this animal. 



(3) Reflex actions. Name those it has. 



7. Make a sketch of one complete canal system. 



8. See text for Summary of Branch and Class characteristics 

 of Porifera. 



