The Louisiana Democrat., 1890-09-10
vENOMoUS SPIDERS.
They Have IL Most Effective Apparatus
for Injecting Their Poison.


Mr.. A. j. Field, in an article in
knowledge on"Venomous Spiders, "says
spider poison appears to have special
effects on certain insects, and the largest
flies are not always the least affected
by it. Insects over which spider poison
has but little influence are usually left
meshed in tho web to struggle until ex-
hausted, before the spider attempts to
devour them. When fly lis bitten by
a spider, its whole body seems siezed
by violent convulsive twitchings, and
death generally occurs after few min
utes.
The spiders poison issues from sac
and duct at the base of its mandibles.
1t closely resembles the venomous mat
ter secreted by scorpions, and is trans
parent fluid, containing traces of formic
acid and albumen. There seems to be
nothing characteristic in its microscopic
appearance. When it is collected from
the poison glands ofseveral spiders and
dried, it will retain its. physiological
properties for many years, and even
after it has been subjected to boiling
temperature its properties are not de-
stroyed.
The spider is provided with most
effective apparatus for injecting its
poison, consisting of modified mandi-
bles, called "falces,' the last joint of
which has hard curved fang, with a
fissure near the point. The muscles
used in closing the mandibles also press
upon the. poison gland, causing the
poison to be expelled through the fissure
into the wound, and thence into the
circulation of the victim.
The re ader should watch common
house-spider spin its web. 1t seems to
take pains, before beginning, to select a
spot where there are chances of obtain
ing plunder, and where it will be se-
cure. 1t then discharges little drop
of glutinous fluid, and creeps up the
wall, joining the thread from one wall
to the other. The first thread thus
formed is drawn tight, and fixed at each
end with other threads. 1t is upon this
outer thread that the durability of the
whole fabric depends. The webs foun-
dation completed, the spider next
makes number of threads parallel to
tho first, and then crosses them with
other threads, the sticky substance Of
which they are formed serving to bind
them, when newly made, to each other.
1t now commences to double and treble
the threads that border its web, secur-
ing the edges as it does SO. Lastly, it
forms kind of tunnel with webbing;
this is to serve as retreat, where it can
conceal itself from its enemies and also
from its prey, and is generally placed in
the angle of the walls.
When the spiders work is done, it
often happens that the approach Of
some large animal or tho approach OF Of
the housemaid's broom will destroy in
a minute the labor of days. In this
case, as soon as the danger is passed
away the spider patiently begins to re-
pair the web.
Old SPIDERS which have neither web
nor the materials to make one, often
hunt about to find out the webs of
other spiders, younger and weaker than
themselves, with which they venture
battle. The invader generally succeeds,
and the younger spider is driven out tc
make new web, and the old spider re-
mains in possession until stronger
spider invades the web and drives it
out. When thus dispossessed the spider
seldom ventures another attack, but
tries to subsist upon the few insects
that may fall accidentally into its
clutches, and eventually dies of hunger.