The Dupuyer acantha. [volume] (Dupuyer, Mont.) 1894-1904, 1895-05-11

Singing of Two Kinds, But Inaudi-
BILE to lunar Ears.

Singing of Two Kinds. But Inaudi-
BILE to Human Ears.
1t is not generally known that some
spiders can make a noise; in fact, it Is
| only recently that this has been estab-
lished beyond dispute, though it was
discovered half a century ago that
some species possess STIMULATING or
| gans like those of a cricket or a grass
hopper. The present state Of our
knowledge concerning these organs,
the method Of their use, and their pur-
| pose is summarized by r. I. Pocock in
says:
In many spiders, owing to the small
size of the organs and the shrillness
of the note. the articulation cannot be
heard by human ears, and we can only
infer from analogy that it is actually
produced. In a spider of the Southern
hemisphere, however, called Thomi-
soides, it is distinctly audible. The or
gans that produce it consist of a scra-
per formed by sharp tubercles. on the
| pdip, duu d IluScu dIed Ou t1e HILL
dible. By drawing the former up and
down over the latter a noise resembling
the buzzing of a bee Is produced. The
palp, is should be explained, is a short
limb formed almost exactly like the
legs, bul never used for walking.
In another group the huge Indian
bird spiders, so-called because they are
said to entrap and eat birds, sounding
organs of a different kind are often
found, consisting of a series of strings
of keys and of strikers, which set them
vibrating.
The purpose of the sounds has been
a much vexed question. The following
re~capitulation of the opinions Of the
best authorities is given by Mir. Po-
cock:
"Stridulating organs in spiders seem
to exist for two distinct and definite
purposes. In the case Of Lephthy-
phantes and of the species referred
originally to T%heridium, the organs are
better developed in the males than the
females, or are exclusively confined to
members of the former SEX. From this
fact, coupled with the circumstance
that the spiders of these two kinds are,
judging by analogy, possessed of au-
ditory organs we may infer, although
as yet without direct proof, that the
male makes use of his sounding or
gans during the period of courtship.
This, as is well known, is a time which
to the male Of every species is beset
with exceptional difficulties and dan
gers, owing to the irascible and vora-
cious disposition of the more powerful
female. who will often rather make a
meal of her sutton than a mate. Con-
sequently, to Soothe her temper and re-
duce her to a proper frame >of mind,
he is often driven to practice various
charms and ingenious wiles. The
males, for instance, of some species of
the Attidae, or jumping spiders, exc
cute fantastic dances and antics, as
described by Mr.. and Mrs. Peckham,
and, like peacocks, make a display the
while of whatever plumes or bright
colors they possess. So that, since it
seems to be established that the fe-
males of the Attidae have in all proba-
bility an esthetic sense which is graft
fed by the sight of gaudy ornaments
ON members of the opposite sex, there
appears to be no great extravaganza in
the superstition that the females Of the
species of Theridium and Lephthy-
| like the females or our song
birds. not to mention nearer allies,
may be charmed by the musical efforts
of their lovers. But whether this be
the object of the stridulation, or wheth-
err 1t be merely used as a sign of the
specific identity Of the approaching
male, the evidence indicates that it
only serves it's possessor in his rela-
lions with the females of the same OF
Of closely allied species.
con the second case, namely, that OF
Thomisoides and the Avicularlidae, In
which the STIMULATING organ is brought
to the same state of perfection in the
females as in the males, the spiders
themselves being by analogy unable t.
hear. the available evidence shows
that the sound has nothing directly tt
do with the relations of one sex to thu
other, but that it functions solely a,
a danger signal, warning enemies t,
keep their distance. While, however
the signal is genuine enough in tn,
large and powerful Aviculariidae, il
Thomisoides it s altogether fraudulent
since the spider, which is relatively
feeble animal, by aping the hummin;
of q bee, succeeds in deluding its hear
ers into the belief that it possesse
certain dangerous qualities to whic
in reality it has no claim"