REACTIONS OF AMCEBA PROTEUS TO FOOD. 415 



The next observation, however, is quite unusual. The Chilo- 

 monas paramceciitm in this case ran into the side of an Amoeba 

 protens that was "flowing into" a curved pseudopodium. In 

 this case the large pseudopodium flowed back along the outer 

 side of the Chilomonas until the tips of the two pseudopodia 

 fused (Fig. 3). 



We have seen three instances of a Chilomonas paramoecium 

 and one instance of a diatom entering the narrow angle between 

 two pseudopodia and coming in contact with the ectoplasm at 

 the apex of this angle. In all these cases the reactions were 

 analogous. The specimen represented in Fig. 4 had a Chilo- 

 monas paramcecium swim into the narrow angle between two 

 pseudopodia and which made repeated contacts at a. The 

 response to this stimulus at a resulted in the formation of pseudo- 

 podia behind the Chilomonas at b and c. 



In contrast with the last observations is one made upon a 

 specimen that had two widely diverging pseudopodia. The 

 general movement of the body was in the larger pseudopodium. 

 A Chilomonas paramoecium came in contact with the middle of 

 the mesial surface of the smaller pseudopodium. The flagellate 

 made a single impact at this point and lay in contact with the 

 ectoplasm. In response to this contact the Amasba proteus sent 

 out a third protoplasmic process from the apex of the angle 

 between the first two pseudopodia (Fig. 5, a), thus placing the 

 object of prey in a narrow angle between two pseudopodia. 

 Before the end of pseudopodium a reached the level of the end 

 of its neighbor it changed its course so as to flow behind the 

 Chilomonas. At the same time the original pseudopodium sent 

 out a secondary one (Fig. 5, b] below its apex to meet the other 

 enclosing pseudopodium. In this way the Chilomonas was en- 

 closed in a food vacuole of about the usual size. 



Other conditions may arise with reference to the capturing 

 of the Chilomonas paramoecium by the Amoeba proteus. Chilo- 

 monas sometimes seems quite indifferent to the contact of the 

 Amoeba proteus. On September 30, a specimen of the latter was 

 observed which came in contact with a flagellate at the apex of 

 its more active pseudopodium (Fig. 6, a, I.) As the pseudo- 

 podium grew the Chilomonas glided along its surface to the 



