390 WM. A. KEPNER AND J. GRAHAM EDWARDS 



November 3, 1916. Pseudopod a moved beneath a quiet 

 Chilomonas until it had travelled to a', figure 9. The pseudopod 

 a' now expanded beneath the Chilomonas to the contour b-b' . 

 A cup was evidently formed about the flagellate, though the 

 details of this cup's formation could not be seen; for eventually 

 the Chilomonas began struggling within a space about as large 

 as was the diameter of pseudopod a'. The space became more 

 and more reduced as the Pelomyxa flowed on, until eventually 

 the Chilomonas lay quiet within a small vacuole at the posterior 

 end of the animal. 



The details of Pelomyxa's reaction to a quiet, motile body, 

 lying beneath the plane of its movement, seem to be the re- 

 verse of those made with reference to an animal that lies above 

 the plane along which the Pelomyxa is moving. 



November 15, 1916. A small specimen displayed currents 

 in the two pseudopods indicated in figure 10. The shorter 

 one of these pseudopods traveled over a quiet paramaecium 

 until its end lay at a. This narrow pseudopod then expanded 

 to contour b-b'. The margins of this expanded pseudopod 

 supported a somewhat circular curtain that was being dropped 

 about the paramaecium. Thus an inverted cup was being 

 formed about the paramaecium, which had been quiet except 

 for the action of its peristomal cilia. While this was taking 

 place, the paramaecium escaped and the modified pseudopod 

 was withdrawn without the completion of the cup. 



Perhaps the most interesting manner of meeting the contin- 

 gency presented by the possible escape of the prey is given in 

 the following reaction. 



November 11, 1916. A Chilomonas was playing in the bay 

 formed between one side of Pelomyxa's body and a desmid that 

 lay in contact with the rhizopod. In response to this but one 

 pseudopod was sent out which advanced to make a contact 

 with the desmid (a, fig. 11). The direction of growth was 

 changed in this pseudopod after it came in contact with the 

 outer segment of the desmid so that its advance was in towards 

 the body-proper along the side of the desmid (b and c, fig. 11). 

 In the meantime the Chilomonas was enclosed at its second 



