THE NERVOUS SYSTEM OF CCELENTERA. 107 



colonial Anthozoa, such as Alcyonium, it is the endodermic 

 nervous system which is the predominant one. A com- 

 munication exists between the ectodermic and endodermic 

 nervous systems in the Anthozoa by way of a loose plexus 

 of cells and fibres, but to what extent this also occurs in 

 Hydrozoa and Scyphozoa we have at present but litde 

 evidence. 



Sydney J. Hickson. 



