The Republican. [volume] (Oakland, Md.) 1877-current, 1884-02-02
ABOUT CRABS.

Grabs are curious creatures. AT the
first glance we can scarcely tell which
is the head. Notice the position of the
eyes, and that will settle the question.
Walking, as they do, forward, back
ward, and even sideways with equal
ease, it seems as if they, too might be
slightly puzzled about their formation,
and so, not stopping to decide which
part is intended to 90 foremost. they
dart off on venture, and in the oldest
manner possible.
They are so abundant on all our sea-
shores that we rarely lift a bunch of
sea-weed or poke among the rubbish
there without disturbing their haunts,
yet they scramble off and hide in the
sand SO quickly that we are not much
wiser for their discovery. Let us pick
up some cast-of' shell and make a
closer examination.
The bodies of higher animals contain
three principal cavities - the head,
thoraX and abdomen. In crabs, on the
contrary, the head and thoraX are so
closely united that we can not distin-
gush them, and they are covered by
the same shell. The proper name for
a head and thorax thus united is '.ceph-
| a-lO-thoraX.'
A crab, consequently, has two prin-
| cipal parasitic cephalo-thoraX and the
abdomen-eacb containing a number of
parts of its own. TO the cephalo-thoraX
are attached five pairs of iointed legs.
The front pair are much larger than
the others, and form the claws. The
| abdomen consists of six parts, but it is
small and inconspicuous, being folded
under the cephalo-thoraX.
The compound eyes of crabs are on
long stalks, and they may be turned in
different directions or folded back into
little grooves in the shell.
Crabs breathe by gills and by
branchia. ellis are leaf-rke plates so
| situated as to be readily bathed with
water They contain a great many
! blood-vessels, and the oxygen in the
water, finding its way through their
delicate walls, mixes with the blood to
purify it, The crabs heart consists of
a single contractile sac.
Grabs are often spoken of as crus-
taceans. The name, / think, will
at once suggest to you animals hay
ing hard crust. AS this crust con-
tains a number of pieces exactly fitted
| to each other, it has been compared to
the armor worn by soldiers in olden
times The manner in which it is shed
during the growth of the crab is curious
and interesting. This hard shell never
increases in size; therefore as the crab
| grows its shell becomes too small, and
it is cast off, looking like the perfect ami
NAL, with eyes and legs attached.
When the proper time for this change
shell, separating from it at all points, and
the animal works its way out. The eX-
hausted creature now remains quietly
in some secluded place, increasing rap
idly in size. until the soft skin again
hardenS into new shell.
This is painful and perilous expert
ence for the poor crabs. Occurring as
it does several times in the summer,
their weak and unprotected bodies fall
an easy prey to their enemies. and they
are devoured even by other crabs which
happen to be in better plight. Now it
is that they are known as 'soft-shelled"
crabs.
Crustaceans. when fully coated with
mail, are strong and destructive, fight
ing among themselves rs well as with
other animals. They eat any small
creatures that come in their way,
whether living or dead. On the other
hand, they themselves are destroyed by
larger animals, and crustaceans form q
large part of the food of star-fish, sea-
urchins, mollusks, and many kinds of
fish and birds, consequently great guam