PROGRESS OF MICROSCOPICAL SCIENCE. 261 
marsh, at Bristol, Pa., he obtained a drop of material for examination 
with the microscope. After a few moments he observed an Ameba 
verrucosa, nearly motionless, empty of food, with a large central con- 
tractile vesicle, and measuring ;!; of a millimeter in diameter. Within 
a short distance of it, and moving directly towards it, was another 
and more active Amceba, the species of which he was not positive. 
It was perhaps the one described by Dujardin as A. limax, by which 
name, for the present purpose, it may be called. As first noticed, this 
Amoeba was limaciform, } of a millimeter long, with a number of 
conical pseudopods projecting from the front broader end, which was 
zg of a mm. wide. The creature contained a number of spherical 
food vacuoles with sienna-coloured contents, a large diatom filled 
with endochrome, besides several clear vacuoles, a posterior con- 
tractile vesicle, and the usual granular entosarc. The A. limax 
approached and came into contact with the motionless A. verrucosa. 
Moving to the right, it left a long finger-like pseudopod curved 
around its lower half, and then extended a similar one around the 
upper half until it met the first pseudopod. After a few moments 
the ends of the two pseudopods actually became connate (the second 
time he had observed this phenomenon), and the A. verrucosa was 
enclosed in the embrace of the A. limax. The latter assumed a per- 
fectly circular outline, and after awhile a uniformly smooth surface ; 
but the central contractile vesicle remained in the same condition, nor 
did he once observe it enlarge or collapse. The A. limax now moved 
away with its new capture, and after a short time what had been the 
head end contracted, became wrinkled and villous in appearance, 
while from what had been the tail end a number (ten) of conical 
pseudopods projected. The A. verrucosa assumed an oval form, and 
the contractile vesicle became indistinct, without collapsing. Moving 
on, the A. limax became more slug-like in shape, measuring about 4 
mm. long, by = mm. broad. The A. verrucosa now appeared enclosed 
in a large oval clear vacuole, was constricted so as to be gourd- 
shaped, and had lost all traces of its contractile vesicle. Subsequently, 
the A. verrucosa was doubled upon itself; and at this period the 
A. limax discharged from one side of the tail end, the siliceous case of 
the diatom, which now contained only a shrivelled cord of endochrome. 
Later the A. verrucosa was broken up into five spherical granular 
balls, and these gradually became obscured and apparently diffused 
among the granular contents of the entosare of the A. limaz. At 
one moment the five granular balls derived from the A.° verrucosa 
appeared to be contained in three vacuoles, and the A. limax had 
amore contracted and radiate form, and then measured 5 mm. in 
diameter. 
The observation, from the time of the seizure of the A. verrucosa 
to its digestion, or disappearance among the granular matter of the 
entosare of the A. limax, occupied seven hours. 
From naked Amcebe, the test-protected Rhizopods were no doubt 
evolved, and it is a curious sight to observe them swallowed, home 
and all, to be digested out of their home, just as the contents of dia- 
toms are digested. It was also interesting to observe the cannibal 
