Two other points remain to be noted. The feet should be examined,
for their structure throws some light on the way in which the Garden
Spider runs so securely to and fro on the radial lines. One of the
legs of a dead specimen should be detached, and its armature of spines
and hairs noted. The foot is armed with three stout claws, which
are pectinated--that is, toothed like a comb, and beneath them are
smaller ones, sometimes described as toothed hairs. It will be easy
to understand what a secure foothold these claws give the animal as it
runs backwards and forwards over the radial lines; for if the web be
shaken by the wind or designedly its owner can take a firm hold with
each foot, and thus have eight separate points of attachment. An inch
hand lens is quite sufficient to give a general idea of the hairy and
spinous clothing of the legs and the position of the claws; but to see
the teeth a higher power--a half-inch--will be necessary.
It is a good plan to choose a freshly killed specimen for the
examination of its spinnerets. If the spider is laid on its back in a
glass dish, gentle pressure on the abdomen away from the cephalothorax
will cause the material secreted by the spinning-glands to ooze out.
This, however, cannot be done if the specimen has been for some time
in spirit. We shall be able to make out six tubes (four of them larger
than the other two) grouped round the anal aperture; but, for the
present, we must take for granted the fact that these are made up of
a number of smaller tubes, so that the end of each spinneret is not
unlike the rose of a watering-can. A good half-inch will give some
indications of this rose-like appearance.
The Jumping Spider (_Sal´ticus sce´nicus_) belongs to a family
the members of which make no web or snare for the capture of prey, but
trust for their food-supply to their skill in stalking flies and other
insects, which they capture by a sudden spring. It is from this habit
that the type-genus and the family have received their scientific and
popular names.
The common British species is extremely abundant, and wherever flies
are plentiful these spiders will not be very far off. This is the case
not only in the country, but also in London and other large towns. It
is a noticeable spider from its coloration--black marked with white.
The eyes are eight in number; though the artist in our illustration
has only represented four. The centre two of the front are the largest
of all, and have been compared not inaptly to bull’s eyes. Two others
are placed on each side of the cephalothorax, so that the eyes form,
roughly, three sides of a square, and the central eyes in the lateral
lines are the smallest. We may represent them thus [image], while the
eyes of the Garden Spider are disposed in this fashion [image].
[Illustration: FIG. 54.--Jumping Spider. (Line shows
natural size.)]
[Illustration: FIG. 55.--Falces of Male Jumping Spider.]
Public-domain text, read in full here on John Shaqi.
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