540 ASA A. SCHAEFFER 



A little watching will show that the spot where things are taken in 

 is close to the small extremity, and that very often one or more pseudo- 

 podia are projected there, so as to encircle a diatom or a green ani- 

 malcule or a piece of alga, which is slowly pressed by them against 

 the Amoeba and then sinks in (p. 230). 



The prey becomes environed by a vacuole, or is tumbled about by 

 the endosarc amidst the jumble of things there (p. 230). 



. . . . long ridges appear on its surface .... (p. 230).^ 



The pseudopodia closed on the granular mass and brought it to the 

 part where the neck of the head joined the main body, and the prey 

 sank into the endosarc. I have repeatedly seen these Amoebae take 

 in food, and it has always been at this particular spot (p. 230). 



. . . . the vesicle is in its very common place, the food enter- 

 ing end . . . . (p. 231). 



As these j^omig forms were watched, it became evident that occa- 

 sionally a minute spore or small navicula like diatom coming into con- 

 tact with the spot where the sticky (hinder) end joined the non-adher- 

 ing protoplasm of the diaphne, sank into the body, and was soon seen 

 streaming along inside, environed by other prey, and a multitude of 

 granules, granular spheres, and masses of protoplasm (p. 234). 



It will be evident from these extracts that Duncan did not ob- 

 serve the essential details of the feeding process. The definite 

 conclusion that food is caught only at the posterior end and not 

 at the anterior end has remained unconfirmed except in a very 

 small number of cases. I am unable to suggest how Duncan 

 might have come to this conclusion. 



As far as I have been able to find, Leidy ('79) first described 

 and figured the essential features concerned in the capture of a 

 living organism by an Amoeba proteus. 



I have had but few opportunities of seeing Amoeba proteus capture 

 living animals. In one instance I saw an individual, as represented 

 in figure ^, plate 1, containing, within a large vacuole, an active In- 

 fusorian, a Urocentrum, and having a second victim of the same kind 

 included in the fork of a pair of pseudopods, the ends of which were 

 brought into contact, so as to imprison the animalcule Avithin a circle. 

 The latter moved restlessly about within its prison, but after a time 

 became motionless, and shortly after the ends of the pseudopods which 

 enclosed it fused together, as seen at c in the figure just indicated. 

 Films of ectosarc extended from the body of the Amoeba towards the 

 fused ends of the pseudopods, and finally the Urocentrum was enclosed 



^ The amebas seem to have been of the species described by Penard as Amoeba 

 nitida, and of the variety figured by Leidy ('79) in plate 1, figure 7. 



