346 PROCEEDINGS OF THE ACADEMY OF [1886. 



OBSERVATION ON MULTIPLICATION IN AMCEB^. 

 BY LIIiLIE E. HOLMAN. 



On the 4th of July, 1886, I was examining the forms of life 

 contained in a Holman life-slide, which had been filled for 

 several hours. It contained different Infusoria, and among 

 other animals, specimens of JEolosoma. But it seemed for some 

 time as if there were no amoebae in the slide, until I discovered 

 a small one near the channel. In shape it seemed like an elon- 

 gated triangle, and was rather torpid, or at least moved but little. 

 While I was examining it, it moved up closer to the line of the 

 channel, and another amo3ba, about twice the size of the first 

 one, came gliding on the scene. It moved up very close to the 

 other, and in a few moments I noticed that it looked as if it were 

 trying to swallow the smaller amoeba, in the same manner that 

 it does its ordinary prey. As I had watched many amoebae and 

 had never seen anything like this, and as I knew that they did 

 not prey on each other, and the question of their conjugation 

 was a very doubtful one, I dismissed the idea of the larger 

 absorbing the smaller, and concluded it was merel}' the fact that 

 they were in too tight a place to allow of their passing each other 

 which gave them this appearance. I watched them constantly 

 for about half an hour, in course of which time I became con- 

 vinced that something unusual was going on. 



The larger amoeba had entirely surrounded the smaller one, 

 which, however, did not seem to lose its vitalit3^ First it seemed 

 to be under the endosarc of the larger, and then above it. 

 Somertimes it would project a pseudopod out from beyond the 

 ectosarc of the larger animal. All the time it was distinctly 

 visible in its own individuality, if one may so call it, and did not 

 at all seem to be trying to escape. I called Mr. Holman's atten- 

 tion to the singularity of their behavior, and expressed my 

 belief that it was a case of either cannibalism or conjugation. 

 He expressed his disbelief in either of these cases, and observ- 

 ing that the water in the slide was evaporating, we allowed a 

 little to creep in under the closed edge of the cover-glass. This 

 seemed to relieve the large amoeba from the constrained position 

 and flat contour which it had assumed, and it immediately com- 



