The Savannah morning news., 1903-09-13

the others.
"organisms Without Organs"
Such, then, are the main facts to be
learned about these obscure jewellers
in the pond. 1t now behooves us to
consider the principal notifications
which have arisen from a comparative
~ simple form like the amoeba, and
which have given rise to such a vast
and varied assemblage of unicellular
animals as we know the protocol to be.
The amoeba has just been called a COM
paratively simple form, and the ad-
verb is used advisedly, for in the very
lowest group of protozoa there is no
trace of either nucleus or contractille
Vacuole. Such primitive forms have
been quantity termed Organisms with
out organs" and they constitute the
very lowest section of the animal king
dom.
The remainder of the unicellular ami
mails are grouped in two main divisions.
In the first of these the body substance
is more or less exposed, and processes
like those described in the amoeba,
which belongs to this division, can be
thrust out at least at one, and gener-
ally at several points. In the second
division, on the other hand, the body is
OF definite shape, its outer layer be-
ing dense, and often surrounded by a
limiting membrane. This feature pre-
vents the formation of processes for To-
comotion and the capture of food, and
hence these necessary duties are per-
formed, as we shall see later, in va
riety Of other ways.
Let us briefly consider the lowly or
ganisms of the division to which the
amoeba belongs. Four different sec
lions of this division have been distin-
guished, according to the nature of the
processes emitted from the body. In
the first of these they are blunt and
nngerlike, and hence the amoeba and
its relatives. must be included here.
The members of this division occur ev-
erywhere-in sea water fresh water,
and even on damp earth. In the sec
ond, they are very slender, branching
and communicating with each other in
the form of a loose network. To this
division belongs those interesting and
beautiful animals known as foramini-
fera, whose tiny shells are so often ad
mlred and studied by the happy possess
sor of microscope. These animals
ore very important from more than one
point of view. Their shells are of the
most various and elegant forms, and
may be obtained with the utmost ease.
One of the simplest methods is to take
a common Turkey sponge as it is pur-
chased in the shop, dry and unused,
and to shake it over piece of dark
colored paper. The fine sand which
falls onto the paper will if examined
with lens, be found to contain quite
number of entire or broken shells of
these animals
Again. some of our shore sands are
largely composed of the empty shells
OF foraminifera, one of the most noted
localities for such objects being a GER
tain bay near Connemara, in Ireland,
where over 100 different kinds have
been collected. The number Of individ-
ual shells in such a locality must far
exceed our powers of calculation or
even imagination, for in a single ounce
of sand from the shores of the Adriatic
one observer counted no fewer than
5000 specimens. The flor of the ocean,
too, over an area whic. has been esti-
mated to comprise about $4,000, 900
square miles, is entirely covered with
mud of which 60 per cent. is carbon
ate of lime derived from the shells of
these tiny animals. Add to this state
ment the fact that many of the chalks
and limestones covering immense tracts
of the earth's surface and forming the
bulk of some of the highest ranges of
mountains are almost entirely COM
posed of the fossil shells of foramini-
fera and the Importance of these mi
| mute animals in the economy of ma
ture will at once be realized.
Flesh Water Inhabitants.
third group of protocol belonging
to the first division comprises a num-
Der of inhabitants of fresh water whose
processes are very long, stiff, and slen-
der, radiating from the body in all di-
rections, and giving rise to an appear
ance like the rays of the sun. Hence
these forms are known popularity as
sun animalcules. They are extremely
beautiful objects under the microscope,
and are usually spherical and free
moving, although sometimes attached
to weeds and other objects by long
stalk. The means by which a sun
anima1cule obtains it's food is interest
ing. When it's prey, which consists of
other and more minute animal and veg
etable organisms, comes in contact with
one of the fine stiff rays it appears as
If paralyzed, and glides along the ray
until it reaches the surface of the body
proper. 1t is then engulfed by projec-
tions of the body substance, as in the
case of the amoeba. If the particle of
food is large then several of the rays
may assist in the process of capture.
The fourth group of animalcuIes
which emit processes of the body-sIIb-
stance for locomotive and feeding pur-
poses contains the equisite little ami
mails known as radiolarians, the beauty
of whose shells cannot be adequately
described, but must be seen to be ap-
preciated. All these creatures are ma
rine, floating on or below the surface
of the ocean when alive, and covering
the floor when dead with their elegant
f1inty skeletons. At least 1000 differ
ent kinds have been described. so that
it is quite unnecessary to remark that
they offer to the specialist subject for
study sufficient to occupy a lifetime.
Radiolarians are characterized by the
fact that the body-substance is divided
into an inner indicated portion and an
outer portion without nucleus, the two
being separated by a membrane which
is perforated so that the body-sub-
stance is continuous between them.
Like the foraminifera, but in less de-
gree, their fossil shells form part of
certain chalky formations, and hence
are of considerable importance from a
geological point of view.
The second main division of the pro-
tozoa contains the higher forms, in
which the body is provided with an out
er and denser portion, which gives to
the animal definite shape not due to
the possession of shell or skeleton IS
in some of the forms above described.
These creatures are known as infuso-
ria, the name arising from the fact
that they are commonly found in In
fusions of hay and other vegetable sub
stances. They are exceedingly COM
mon in nearly all ponds and bitches.
and may easily be recognized by their
rapid movements. AS we should ex-