426 WILLIAM A. KEENER AND WILLIAM H. TALIAFERRO. 



EXPLANATION OF PLATE II. 



FIG. 3. Shows a Chilomonas lying between a lateral and a terminal pseudo- 

 podium. The response to the contact or contacts made by the Chilomonas was 

 the lateral and posterior growth of only the terminal pseudopodium. The suc- 

 cessive steps in the advance of this pseudopodium is indicated by the broken lines. 

 X333- 



FIG. 4. The Chilomonas by advancing and retreating made three contacts at a. 

 The response of the Amoeba to these contacts was not at the point stimulated but 

 at points (&) and (c). From these points secondary pseudopodia grew towards 

 each other and fused behind the prey, as indicated by the dotted lines. X333. 



FIG. 5. A Chilomonas entered the wide angle between the two large pseudo- 

 podia in the direction indicated by the arrow. When it met the Amoeba it lay in 

 contact with the ectoplasm. In response to this contact a small secondary pseudo- 

 podium (&) arose behind the prey and a large pseudopodium (a) arose from the 

 apex of the inter-pseudopodial angle. X333. 



