GENUS AMCEBA— AMCEBA PEOTEUS. 45 



I have rarely bad the opportunity of directly observing Amxba proteus 

 swallow food, mainly from the circumstance that I did not sufficiently often 

 watch the animal a proper length of time for the purpose. 



Mr. Duncan, in a recent publication,* intimates that the usual position 

 in which the Amoeba? take their food is at the posterior extremity of the 

 body, which I am inclined to think, from some later observations I have 

 made on the allied genus Dinamoeba, is correct. 



On the other hand, I have repeatedly observed Amoeba proteus dis- 

 charge the remains of its food; the usual position being at the posterior 

 extremity of the body, in the vicinity of the nucleus, as represented in figs. 

 3, 4, pi. I. The excrementitious matters commonly consist of brownish or 

 colorless balls and granules, empty cells of algae, or others with the brown- 

 ish, shriveled remains of their contents, diatom shells, etc. The discharge 

 is rather sudden, and is often accompanied with the escape of some viscid 

 liquid. The temporary orifice abi-uptly closes, leaving no trace of its pre- 

 vious existence. 



From the concurrent testimony of observers, it would appear that the 

 Amoeba? may take food at any point of the surface of the body; and the 

 discharge of matters may likewise occur in any position. 



I have had but few opportunities of seeing Amoeba proteus capture 

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

 5, pi. I, containing, within a large vacuole, an active Infusorian, a Urocen- 

 trum, 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 within 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 in a vacuole like that in the interior of the body 

 of the Amoeba. Having carefully watched the latter for some time, the 

 two vacuoles containing the captured Urocentrums were seen gi'adually 

 to diminish in size, the contents were reduced to the usual size of ordinary 

 food- balls of the endosarc, and all trace of the previous character of the 

 victims was completely lost. 



* Popular Science Review, 1677, 217. 



