PLATE 4 



EXPLANATION OF FIGURES 



13 A. Pelomyxa reacting to a group of paramaecia. All of these ciliates 

 escaped by the time pseudopods b and b' had formed. In this case a food-vacuole 

 was completed. 



B. The same pelomyxa reacting to a paramaecium, which escaped when pseu- 

 dopods a b-a', and c were formed. After the escape of the prey, the pseudopods a 

 b-a', and c were retracted. X 100. 



14 Pelomyxa reacting to paramaecium four times in a similar manner. 

 After this, its fifth reaction was changed by having the tapering pseudopodium 

 expand at the end and thus embrace the ciliate by pseudopods g and g'. X 100. 



406 



