10 
LIFE, IN ITS LOWER FORMS. 
hundred thousand millions would be contained in a cubic 
inch ; and as they are found swarming in water to such 
a degree as that each is separated from its neighbours 
by a space not greater than its own diameter, a single 
drop of such water has been estimated to contain a thou- 
sand millions of living active beings. If we take a bunch 
of leaves, of the common sage, for example, or a few twigs 
of hay, and, tying them into a bundle, suspend them in a 
jar of water, allowing the contents to remain untouched, 
but exposed to the air, some interesting results will 
follow. If we oxamine it on the second day, we shall 
find a sort of scum covering the surface, and the whole 
fluid becoming turbid, and slightly tinged with green. If 
now we take, with the point of a quill or a pin, a minute 
drop of the liquid, and examine it with a good microscope 
under a magnifying power of about two hundred diameters, 
we discover the water to be swarming with animal life. 
Immense multitudes of minute round or oval atoms are 
present, which move rapidly with a gliding action. These 
are animals of the genus Monets just described. Among 
them we shall probably see other bodies still more minute, 
resembling short lines, most of which are seen to be com- 
posed of more or fewer bead-like bodies, united into a chain. 
These occasionally bend themselves, wriggle nimbly, and 
effect a rather rapid progression in this manner. The 
scum, or transparent pellicle, is found to bo composed of 
countless millions of these latter, congregated about as 
is about 100 feet in length. The smallest is the Twilight Monad above men- 
tioned, whose dimensions are 12000 th of an inch. It is evident that the 
middle term between these extremes is £d of an inch, which is about the 
length of the common house-fly, which may be therefore considered as an 
animal of medium size in creation. 
