that were suspended by a single thread, he
several times observed that the slightest breath
of air bore them away in a horizontal line out of
sight. Mr. Darwin repeatedly saw this kind of
spider, having crawled up to an eminence, elevate
its abdomen, send forth a thread, and then sail
away with unaccountable rapidity. He thought,
but he is not sure, that, before starting, the
spider connected its legs together with the most
delicate threads. One day when at Santa Fé, a
spider about three-tenths of an inch in length,
resembling a citigrade, and quite different therefore
from the gossamer spider, while standing
upon the summit of a post, darted forth three
or four threads from its spinners. These glittering
in the sunshine, might be compared to
rays of light; they were not, however, straight,
but in undulations, like a film of silk blown by
the wind. They were more than a yard in length,
and diverged in an ascending direction. The
spider then suddenly let go its hold, and was
quickly borne out of sight. The day was hot
and calm, but the atmosphere can never be so
tranquil as not to affect a vane so delicate as the
thread of a spider's web. The effect of a current
of heated air is evident when we look either at
the shadow of an object cast on a bank, or over
a level plain at a distant landmark, and this
current would probably be sufficient to carry
with it so light an object as the little spider
with its thread.

The habit of sailing through the air is probably
as characteristic of certain species as
that of diving is of the silvery spider of the
ponds. Upon the whole, Mr. Charles Darwin
deems it probable that these tiny aëronauts
do tie their feet with fine lines forming
artificial wings, and "regrets he did not
determine the point with accuracy, for it
would be curious if a spider should be able to
take flight by the aid of temporary wings."
According to Mr. Blackwell (in the part of
his work on British and Irish Spiders published
last year by the Ray Society), if we have
understood that gentleman correctly, these temporary
wings made by the spiders have been
described to be threads of viscous matter spread
out into a sort of ribbon, serving as a sail or
float for the tiny aërial voyagers.

Mr. Blackwell denies that spiders can dart
lines from their spinners. He emphatically
says they are utterly incapable of it. Many
intelligent naturalists, he continues, maintain
the opinion that spiders can forcibly propel
or dart out lines from the spinners; but
when placed on twigs, set apart in glass
vessels with perpendicular sides, containing
water enough to immerse their base
completely, all the efforts they make to escape
uniformly prove unavailing in a still atmosphere.
However, should the individual thus
insulated be exposed to a current of air, either
naturally or artificially produced, the abdomen
is immediately turned in the direction of
the breeze, and the viscid secretion being carried
out in a line by the current, it becomes connected
with some object in the vicinity and enables
them to regain their liberty. When
the air is undisturbed they cannot, but in
an inhabited room they can, perform this
operation without difficulty, the air being agitated.

Such is the decided deliverance of Mr. Blackwell;
but we are compelled to say that we have
performed the experiment he suggests, and obtained
exactly contrary results. Many years
ago we collected all the spiders we could find in
the old castle of Ellon, Aberdeenshire, and put
them on the bottoms of up-turned teacups, placed
in saucers full of water. Most of the spiders did
precisely what Mr. Blackwell describes, and
showed themselves incapable of escaping from
their insulated elevation, without the aid of a current;
but one individual astonished us. He put
out a thread in a straight horizontal line, a thread
some five or six inches long, and slowly turning
his abdomen in all directions, made the thread
box the compass, as the sailors say. We were too
young, too ignorant, and too far from books, to
ascertain the species to which this individual belonged.
But it proves that there are spiders
which can do something more than put forth filaments
upon the currents of the air, for it proves
that they can stiffen their threads for special
purposes.

Until the other day we knew of no testimony
corroboratory of these observations, but we find
them confirmed by other observers, and by authorities
no less illustrious than Latreille and Lister.
In the edition of Cuvier's Animal Kingdom, published
in English in 1833, Latreille says: "Lister
has asserted, that the spiders ejaculate and dart
out their threads in the same manner as the porcupines
shoot out their quills, with this difference,
that the latter weapons, according to the popular
opinion, are detached from the body, while
in the spider these threads, though pushed to a
distance, remain attached to the animal. This
feat has been considered impossible. Nevertheless,
we have seen threads issuing from the
nipples of some crab spiders (Thomisi) directed
in a right line, and forming, as it were,
movable radii when the animal moved circularly."

By far the most extraordinary statements respecting
the faculty possessed by certain spiders
of darting forth threads, are to be found in a work
entitled Experimental Researches, published
by a Mr. John Murray, a fellow of the Antiquarian,
Linnæan, Horticultural, Geological,
Wernerian, and Meteorological Societies. The
ascent of the spider, this writer believes, will be
found connected with the meteorology of the
atmosphere, and the observation of its curious
habits will lead to some useful practical results.
The oil of a particular lamp in the church of St.
Eustace at Paris being consumed, and the lamp
extinguished every morning, the sexton watched,
sitting up several nights, and at last saw a
spider of enormous size descend the chain or
cord and drink up all the oil. A spider of
immense size was detected, also feeding on the
oil of a lamp, in the cathedral of Milan. When
taken and weighed, this spider is said to have