224 
POPULAR SCIENCE REVIEW. 
The question of course arose, What was the early shape and 
what was the course of life of this very active Amoeba? It 
could not be answered from the results of last year’s work, but 
during the months of April and May of the present year the 
same stream-bottom yielded the required evidence. The smaller 
of these Amoebae (fig. 28) seen moving about the confervse and 
on the glass of a shallow live-cell box had all the characteristic 
movements of the form just described ; but the minute creature 
had a very small end which never dilated or expanded like the 
opposite termination of the body, and an extremely actively 
moving pale endosarc. The movement was always with the 
broad end forwards. The bulk of the Amoeba moved over 
things which made no impression on it, but the small end was 
sticky and often adhered to diatoms, and there was often a 
struggle between them, the affair ending in a sudden separation 
with a jerk. As these young forms were watched, it became 
evident that occasionally a minute spore or small navicula-like 
diatom coming in contact with the spot where the sticky end 
joined the non-adhering protoplasm of the diaphane, 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. These Amoebae grew rapidly, and 
had an extraordinary power of finding food. They clung to the 
edges of the mud or confervoid mass in the cell, and if they 
accidentally roamed away, they began to move the front end 
first to the right and then to the left, stuck their small end 
downwards, and elevated the rest of the body and searched in all 
directions for something solid to touch. Every now and then 
a rush or flow of transparent diaphane would come out of the 
sides or large end, but never from the other ; and part of the 
endosarc would often follow. But long sharp pseudopodia, or 
even long blunt ones, were never projected. As growth pro- 
ceeded, several contractile vesicles appeared ; and finally the form 
already described was assumed. Moreover, the final fate of this 
remarkable kind appeared to be that the quiet stage ended in 
one of encystment ; that is to say, the outer part of the thin 
diaphane became more solid, the whole assuming the permanently 
globular form without movements. Then rupture of the side 
occurred after some days, and myriads of minute round masses 
with a spot in their midst escaped, each to develop into a tiny 
mobile Amoeba. 
It would appear that these two Amoebse have the same kind 
of life cycle. First a 'minute globe of protoplasm with a trans- 
lucent spot in the midst enlarges in diameter, and assumes an 
elongate form ; then as growth proceeds, it becomes active, 
takes food at one spot, and moves in one direction. An endo- 
sarc with vacuoles and contractile vesicles becomes more and 
