ARTHUR HESS 49 



ance than anything you ha\'e shown. The processes in your sections 

 of Hydra epidermis look to me hke temporary cytoplasmic pseudo- 

 podia. They certainly don't have the same well organized distribu- 

 tion that is seen, for example, in the epidermal cells of corals where 

 the microvilli are arranged in a regular ring around the base of the 

 flagella (Goreau and Philpott, 1956. Exptl. Cell Research 10:552). 

 I'm also interested to see that the epidermal cells of Hydra are not 

 flagellated. 



HESS: All the flagella of Hydra arise from endodermal cells and 

 extend into the lumen. 



GOREAU: We've never found more than one flagellum per cell, 

 whereas you seem to think there are more than one. 



HESS: Yes, in the gastrodermis, each cell apparently has from two 

 to four flagella. 



