84 
THE NATURALISTS’ COMPANION 
rush backwards and forwards, draw- j 
ino- towards and repulsino- eacli otiier. j 
or resting placidly and rocking them¬ 
selves, as if they cradled on the waves : 
of an extensive sea. These are no do- • 
lusions; they are real living creatures, j 
for they play with each other, laisli I 
violently upon one another, thev wliirl i 
round each other, they free and propel | 
themselves, and run from one plafa* to | 
another in order to renew the game! 
with some other little 
creature, or madly 
they precipitate them¬ 
selves upon one an¬ 
other, combat and 
strugg’le until the one 
conquers a n d the 
other is subdued; or 
carelessly' they swim, 
until 
rapaci ^ 
anew. 
Under the general 
heading, P r o t o x o a, 
comes the order of 
creatures which are 
separated from the 
diatoms and desmids 
and regarded by^ naturalists as ani¬ 
mals. The name means “first or simp- 
list animals.” In most cases, except 
in the infusoria, these creatures have 
neither mouth nor stomach, and in' 
none of them can the organs of sense 
be detected. Excepting the sponges 
they are very minute and only to be 
seen under the microscope. 
This group includes Ehizopods, 
sponges, animals haying root-like feet 
or appendages, and Infusoria. | 
In all the organisms of the Rhizo- 
pods the body' is composed of a simple 
geletinous substance, to which the 
term “sarcode” is applied. All loco¬ 
motion is performed by^ the protrusion | 
of processes which from their function 
are termed “pseudopodia” or false feet. 
On placing one of these creatures 
under a microscope, it is seen to re¬ 
semble a mass of sonu' transparent 
jelly', altogether devoid of life. Soon, 
however, the animal begins to push 
out in various directions portions 
(pseudopodia) of the geletinous mass 
of which it consists, and by the alter¬ 
nate expansion and retraction of these, 
it effects a slow and someAvhat irreg¬ 
ular locomotion. The amoeba.as shown, 
belongs to this class. 
The term Infusoria as orriginally 
used was almost sy nonyinous ' with 
YORTICELLA. 
that of animalcules, but it is now very 
much restricted in its significations. 
It was first made use of by' Otto Fi-ed- 
erich Muller, and was adopted by (,’uv- 
ier, who made it the last class of Radi- 
ata; but their radiated structure has 
not been established. No distinct trace 
of nervous matter has been found. 
The Vorticelli is a beautiful variety 
of infusoria. There are seyeral species 
inhabiting ponds or stagnant water. 
Each bell-like form is attached to a 
twig by a -slender thread, and waves 
back and forth in the water with the 
footstalks or thread fully stretched. 
This species usually increases by self- 
diyision. The globular bell becomes 
flattened, then notched, and lastly di¬ 
vided (b).when the newly'formed bells 
become isolated (c). swims away-, and 
