spines upon their hind legs for heckling or
combing, twisting or curling, certain of their
lines into the curls or flocculi characteristic of
their snares.

The students of spiders have long differed in
reference to their faculty of shooting forth their
lines in a straight direction, and without the aid
of any current of wind. Mr. Blackwell affirms
that a current of air is indispensably necessary
for this purpose. " Many intelligent naturalists,"
he says, " entertain the opinion that spiders
can forcibly propel or dart out lines from the
spinners; but when placed on twigs set upright
in glass vessels with perpendicular sides,
containing a quantity of water sufficient to immerse
their bases completely, all the efforts they make
to effect an escape uniformly prove unavailing
in a still atmosphere. However, should the
individuals thus insulated be exposed to a current
of air, either naturally or artificially produced,
they immediately turn the abdomen in
the direction of the breeze, and emit from the
spinners a little of their viscid secretion, which,
being carried out in a line by the current,
becomes connected with some object in the
vicinity, and affords them the means of regaining
their liberty. If due precaution be used in
conducting this experiment, it plainly demonstrates
that spiders are utterly incapable of
darting lines from their spinners, as they cannot
possibly escape from their confinement on the
twigs in situations where the air is undisturbed,
but in the agitated atmosphere of an inhabited
room, they accomplish their object without
difficulty. Similar means are frequently
employed by spiders in their natural haunts for the
purposes of changing their situation and fixing
the foundation of their snares."

But fallacies lurk in generalities, and with
all due deference to Mr. Blackwell, it must be
said that he lays down the law too largely when
he decides that "spiders," meaning all spiders,
"are utterly incapable of darting lines from
their spinners."

The different kinds of spiders have different
kinds of spinnerets, adapted for different kinds
of feats. The skin of the body of spiders
consists of three layers; one, horny and hairy,
and more or less transparent; another, soft
and pigmentary; and a third, a network of
muscular fibres adapted for compressing the
abdomen. The spinnerets, which are generally
six in number, are arranged in pairs.
The hind pair is often prolonged, and three-
jointed. There is in the ciniflonidæ a fourth
pair planted in front, which are short,
compressed, and unjointed. The spinnerets are
moved by diverging bands of muscles connected
with the surrounding skin. Inside the abdomen,
nearer the base than the apex, there is a
point opposite the orifice of the oviduct in the
female, from which bands of muscles radiate.
They keep the abdominal organs in their places,
some of them being inserted into the skin both
on the dorsal and ventral surfaces, and others
running straight backward (in bundles of
strongly striated fibres, like those moving the
legs) into the spinnerets. The silk is secreted in
sacs or bags, and twisting or branching tubes of
various shapes and sizes, each furnished with a
distinct excretory duct, ending on the surface of
the spinneret.

There are four varieties of spinning glands.
There are, first of all, the glands found only in
the ciniflonidæ. These glands consist of many
tiny cells, each having a nucleus and a duct,
which are situated just beneath the supplementary
spinnerets, supplying them with the fine
silk forming the flakelets or flocculi of the
ciniflo (Clubiona abrox and ferox). All the
spiders of this group at present known are
natives of Europe, Madeira, Upper Canada, and
South America. They select for their retreats
crevices in rocks, walls, and trees; the insides
of buildings, and the foliage of shrubs. Their
snares are highly complicated, and distinguished
by filaments which have been curiously curled
by their combs.

The second variety of glands supply chiefly
the front and hind pairs of spinnerets. These
glands consist of an immense collection of oval
or fusiform cells with fine elastic ducts secreting,
probably, the finer threads of the webs and
egg-bags.

The third variety of glands are often of a
very large size, especially in the garden-spiders.
They contain cartilaginous sacs or convoluted
tubes, firm, hard, brittle, and transparent, with
ducts which are not elastic. They are supposed
to secrete the adhesive lines which are placed
upon the geometric webs.

The fourth variety of silk glands most probably
produce the gossamer of the flying or
aëronautic spiders, being numerous in Lycosa saccata
and Thomisus cristatus. They consist of
membranous sacs and tubes, some vermiform, others
club-shaped, and others furnished with branched
cæca or blind tubes. They have fibrous walls
and elastic ducts, with a fibrous external coat,
breaking into distinct rings when the duct is
stretched. The sacs and ducts have a strong
contractile and expulsive power. These glands
probably secrete the stronger and larger lines
which form the frames of the webs.

Mr. Meade, the author of these careful and
minute observations upon the spinning glands,
found that the glands and ducts of the last-
mentioned kind of spiders were surrounded by
a highly fibrous contractile coating, resembling
the coating of the arteries in man and the
higher animals. This contractile coating must
enable the spiders to eject the silky fluid with
considerable violence. I am able to confirm
this physiological inference by the results of
decisive experiments. Many years ago, having
carefully excluded the air from my bedroom, I
placed spiders upon the up-turned bottom of
a teacup, and then put the cup, mouth downward,
into the midst of a saucer full of water. Most
of the spiders I tried this experiment upon
went down the outside of the cup all round,
and, when they felt the water, went up again,
remaining there helpless, discouraged, and
bewildered; but the particular spider in question,