ON THE FEEDING HABITS OF AMEBA 541 



in a vacuole like that in the interior of the body of the Amoeba. Hav- 

 ing carefully watched the latter for some time, the two vacuoles con- 

 taining the captured Urocentrums were seen gradually 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 (p. 45). 



An individual of the kind just described (an A. proteus) I had the 

 opportunity of seeing swallow and digest one of another species, the 

 Amoeba verrucosa. The steps of the process I have attempted to 

 represent in figures 13-19, plate VII, and they occurred as follows: 



In a drop of water squeezed from mud adhering to the roots of the 

 plant Ludwigia, collected in a half dried marsh, in the month of August, 

 I noticed an active Amoeba, as seen in figure 13. It was of elongated 

 triangular, snail-like form, with the anterior broader extremity' ex- 

 tended into a number of conical antenna-like pseudopods. The pos- 

 terior end was somewhat coarselj^ papillose, and from the left side pro- 

 jected two conical pseudopods like those in front. Observing an Amoe- 

 ba verrucosa, figure 12, in its usual sluggish condition, lying almost 

 motionless, directly in the path of the former, I was led to watch whether 

 the two would come into contact and what would be the result. 



The A. proteus contained a number of large food- and water-vacuoles, 

 together with a single diatom. The contractile vesicle occupied the 

 usual position and exhibited the usual changes. The A. verrucosa, 

 besides the granular protoplasm, appeared to. contain nothing but a 

 conspicuous contractile vesicle, and this remained michanged. 



The snail-like Amoeba reached the A. verrucosa, and turning with 

 tail end towards the right, the bodj^ shortened, and a pair of digitate 

 pseudopods extended from the head and embraced the latter in the 

 manner represented in figure 14. The conjoined ends of the pseudo- 

 pods fused together, and the animal reversed its direction of move- 

 ment, while the A. verrucosa gradually sank deeply within its body, 

 and assumed the appearance of a large sphere, still retaining its con- 

 tractile vesicle unchanged, as represented in figure 15. The snail-like 

 A. proteus assuming nearly the original shape, as first noticed, then 

 moved about after a while and presented the appearance seen in figure 

 16. The tail end of the body was elongated and papillose, and the 

 swallowed Amoeba, reduced in size, had lost its contractile vesicle and 

 become oval in shape. Later, the A. proteus appeared more slug like, 

 while its victim had become pyriform and striate, and was then in- 

 cluded within a large water-vacuole, as represented in figure 17. Sub- 

 sequently, the A. proteus was observed to discharge the diatom, pre- 

 viously noticed in the endosarc, from the side of the posterior narrow 

 end; and the A. verrucosa, within its now globular water-vacuole, had 

 become bent upon itself, as seen in figure 18. Still later, the body of 

 the A. verrucosa appeared to have become broken up into five spherical, 

 granular balls, as seen in figure 19, which rolled about among the other 

 constituents of the endosarc of the A. proteus. These observations 



