STUDIES AMONGST AMCEBJE. 
225 
more apparent, but still only arbitrarily divisible from the 
diaphane ; and a nucleus is always present, although often seen 
with difficulty. As growth proceeds, one kind projects blunt 
pseudopodia very readily, and changes its shape constantly ; and 
the other puts forth rounded flowings, but maintains its general 
outline. The first kind becomes quiescent, evacuates much, 
and even gets rid of granules, which are minute Amoebae, and 
at last either bursts or encysts and bursts. The other kind has 
a roaming stage prior to its quiescent condition, which ter- 
minates in encysting, and subsequently in what may be called 
swarming of its included parts. 
The commonest Amoeba differs from the very lively form, and 
is so transparent and so slow in its ever-progressing change of 
shape that it may be readily passed over unnoticed when young. 
It occurs everywhere on the mud, vegetation, and on the glass, 
as well as occasionally in mid-water, where it has been wafted 
by the currents of some Vorticellae or other whirling animalcula. 
Visible as a minute glairy spot when in its early stage, it may 
grow to inch in length, and then, when crammed with food, 
is a very fine object. Taking a large one as an example, 
it will be found that when on the glass (fig. 1) it looks very 
flat and very transparent, the endosarc hardly differing from 
the diaphane in its light-transmitting powers. Numerous pro- 
jections of the diaphane (pseudopodia) are seen all around ; 
some are blunt, and others are sharp, and several circular spaces 
readily transmitting light are to be noticed in the midst of 
it. After a while a languid movement occurs ; a process 
is enlarged, another may move its free end, a new one is slowly 
protruded, and one of the clear spaces shuts up with a quick 
motion. By-and-by the creature begins to change its position, 
and then the invariable hand- shaped Amoeban outline is assumed, 
that is to say, one end becomes smaller and the opposite larger ; 
the largest pseudopodia and rounded occasional swellings are 
at the large end, which invariably moves first and in advance. 
Should any obstacle come in the way, the body flows on either 
side, and may spread out in a wonderful manner ; but the small 
end has a greater density than the other, and does not give way, 
so that the movement takes place in a sliding manner round the 
object, and sooner or later the old and normal outline is seen. 
Many of the clear spaces in the endosarc are evidently not 
capable of contracting, but they are of all sizes, and sometimes 
a very large one may exist. 
These vacuoles (fig. la) arise spontaneously or else are formed 
around some minute object which has got into the Amoeba. 
They are digesting spaces. Amongst them may be seen a semi- 
lunar space (6), through which light passes readily, and it bounds 
a dark body which, although usually near the small end of the 
