144 
[Aug. 24, tgOt. 
A.n Outing in Acadia* — VIIL 
BY EDWARD A. SAMUELS. 
The biting apparatus of the spider is a most remarkable 
piece of mechanism, and as seen under the microscope 
is an exceedingly interesting object. 
"No one," saj's Professor Rymer Jones, "who looks at 
the armature of a spider's jaws can mistake the intention 
with which this terrible apparatus was planned. Murder 
is engraved legibly on every piece that enters into its com- 
position." 
Gosse, the eminent microscopist, in describing the jaws, 
says : 
"There are in front of the head two stout, brown 
organs, which are the representatives of the antennae in in- 
sects, though very much modified irt form and function. 
Tliey are here the effective weapons of attack. Each 
consists of two joints — the basal one, which forms the 
most conspicuous portion of the organ, and the terminal 
one, which is the fang. The former is a thick, hollow 
case, somewhat cylindrical, but flattened sidewise, formed 
of stiff chitine, covered with minute transverse ridges 
on its whole surface, like the marks left on the sand by 
"Fang of spicier showing orifice (o) through which venom is 
ejected. 
the rippling wavelets, and studded with stout, coarse, black 
hair. Its extremity is cut off obliquely, and forms a fur- 
row, the edges of which are beset with polished conical 
points resembling teeth. To the upper end of this fur- 
rowed case is fixed, by a hinge joint, the fang, which is a 
curved, claw-like organ, formed of hard chitine, and con- 
sisting of two parts, a swollen oval base, which is highly 
polished, and a more slender tip, the surface of which has 
a silky luster from being covered with fine and close-set 
longitudinal grooves. This whole organ falls into the 
furrow of the basal joint, when not in use, exactly as the 
Palpus of Lingphia. 
blade of a clasp knife shuts into the haft; but when 
the animal is excited, either to defend itself or to attack 
its prey, the fang becomes stiffly erected. 
"On examining the extreme tip of the fang, we see that 
it is not brought to a fine point, but that it has the ap- 
pearance of having been cut off slantwise just at the tip, 
and that it is tubular. Now this is a provision for the 
speedy infliction of death upon' the victim, for both the 
fang and the thick basal joint are permeated by a slender 
niembranous tube, which is the poison duct, and which 
terminates at the open extremity of the former, while at 
the other end it communicates with a lengthened oval 
sac, where the venom is secreted. 
"When the spider attacks a tly it plunges into its victim 
Palpi of spiders corresponding to ajatennffi of insects. Palpus of 
VValkeneara. As seen in microscope. 
the two fangs, the action of which is downward, and not 
•from right to left, like that of the jaws of insects. At 
the same instant a drop of poison is secreted in each gland, 
which, oozing through the duct, escapes from the per- 
forated end of the fang into the wound, and rapidly pro- 
duces death. The fangs are then clasped down, carrying 
the prey, which they powerfully press against the toothed 
edges of the stout basal piece, by which means the nu- 
tritive fluids of the prey are pressed out, and taken into 
the mouth, when the dried and empty skin is rejected.'' ■ 
I have stated that the spider in attacking her prey buries 
her fangs in her victim and waits with these instruments 
imbedded until the insect is dead. That this is not always 
her method of killing is well shown by Mr. E. Holse, an 
English naturalist, who states that she sometimes en- 
velops her victim in silk immediately after the first in- 
cision, and while the insect is still struggling; sometimes 
she envelops it first and bites it afterAvard, and, finally, 
sometimes envelops and leaves the prey suspended 
without attempting .to_ inoculate the poison at all. 
Tf the web contains no other capture, she drags the 
insect to the center, there to feed upon it at her leisure. 
As has been well stated by Dr. L. G. Mills,. the rapidity 
and fatality of the action ol the poison has been fre- 
quently been a subject of remark. The following simple 
observation sets it in a clear light: A stout fly became 
entangled in the web of a spider; quick as lightning out 
darted the spider and seized the fly, and equally quick was 
the interference to the rescue. It was relieved and set at 
liberty. The fly then walked quickly up a window pane, 
stopped a while, brushed its wings with its hind 'feet, 
rubbed its feet and dressed itself. This was the action of 
a minute. It then walked about again, apparently all 
right. Presently it stood without motion, and after a few 
seconds, when touched, it was found to be scarcely able to 
raise its feet, and after a few seconds more it was quite 
dead. 
In enveloping her prey, the spider, with marvelous dex- 
terity, turns her victim round and round, simultaneously 
drawing out a row of threads by means of the fourth pair 
of legs; with the latter she rapidly sweeps them, ai it 
were, over and over the body of the revolving insect ; in 
this way the whole body is very soon .surrounded by a 
sort of cocoon. There are some species of spiders wh ch 
dispense with the use of any snare by web or otherwise, 
but. like the predacious animals, rely upon their spring 
alone in overpowering their prey. Of these, our common 
black and white spider is a familiar example. When she 
spies a fly at a distance, she approaches it as a cat does 
a bird, softly, step by step, and seems to measure her 
distance from it by the eye; at length, when she judges 
that she is within reach, she darts on her victim with 
such rapidity and so true an aim that she very seldom 
misses it. 
Those persons who have seen a spider thoroitghly en- 
raged have no doubt noticed the wonderful brilliancy 
of the eyes : they seem to glow with the intensity of car- 
bon points in an arc light, or of the facet of a- fine dia- 
mond. The eyes are generally eight in number, and they 
are arranged on the forehead in various positions, accord- 
ing to the variety of spider and its habits. Professor 
Owen says the variety in the arrangement of the ocelli of 
spiders always bears a constant relation to the general 
conformation and habits of the species. Dujes has ob- 
served that those spiders which hide in tubes or lurk in 
ensued, lasting at least a minute. The spider had no 
chance with his enemy, who soon stung him to death 
[sic], losing a leg only during the fight. After resting a 
few moments the wasp circled around again, evidently 
> Eye of Spider, 
obscure retreats, either underground, in the holes or fis- 
sures of walls, or rocks, from which they only emerge to 
seize a passing prey, have their eyes aggregated in a close 
group in the middle of the forehead, as in the bird-spider, 
the clotho, etc. Those spiders which inhabit short tubes 
terminated by a large web exposed to the open air have 
the eyes separated, and more spread upon the front of the 
cephalo-thorax. Those spiders which rest in the center 
of a free web, and along which they frequently traverse, 
have the eyes supported on slight prominences,^ which per- 
mit a greater divergence of their axes. This structure 
is well marked in the genus Thomisa, the species of 
which lie in ambuscade in flowers. Lastly, the spiders 
called Erranles, or wanderers, have their eyes still more 
scattered, the lateral ones being placed at the margins 
of the cephalo-thorax. 
The spider has no friends, and it has manj'^^ active 
enemies. Among these, perhaps the most unrelenting and 
implacable are the so-called mud wasp and certain varieties 
of ichneumon flies, of which there are a dozen or more 
species, which are placed in a number of differetit genera. 
As we, perchance, are watching a spider as it moves, 
about on its silken platform awaiting the approach of a fly 
or other insect prey, we notice that it suddenly assumes a 
nervous, agitated demeanor, and in a few moments en- 
deavors to hide from some approaching enemy. Our at- 
tention is now attracted by a wasp-like insect which, in its 
buzzing flight, draws near, and after circling around the 
spider, attacks it with a great deal of energy and spirit. 
A battle royal now ensues, which almost invariably termin- 
ates with the wasp as victor. 
A correspondent of the late Dr. T. W. Harris thus 
describes one of these encounters : 
"A very large spider was attacked by one of the small, 
blue mud wasps or dirt daubers, not half his size, and on 
the ground. The spider seemed much alarmed, and man- 
aged to fend off his antagonist, and escaped at a rapid 
pace, doubling and winding. The wasp seemed to have 
lost him for several seconds, but presently it circled 
round like a well-trained fox hound, and on striking the 
trai] ran it closely through all the doublings and wind- 
ings of the spider, overtaking and attacking him again. 
This was repeated two or three times, the wasp clearly 
trailing the spider as a hound would a fox. At length he 
succeeded in stopping the spider, when a capital fight 
Poison gland of wasp. Greatly magnified. 
selecting a smooth path, along which he dragged with 
much difficulty his bulky prey. The moment he met with 
an impediment, dropping the spider, he circled round 
again, and invariably chose a smooth path." 
The distance traversed by the wasps in thtiS dragging 
their prey to the tombs in which they are to be placed is 
sometimes very great. Don Felix Azara, as quoted by 
Wasp's sting and point of a cambric needle. 
Darwin, states that he saw one of these wasp-like insects 
dragging a dead spider through tall grass in a straight 
line to its nest, which was 163 paces distant. 
The spider thus defeated and apparently killed, is not in 
reality dead, but it is rendered powerless to move, is, in* 
short, paralyzed by the sting of the insect, and in this con- 
dition it is carried to a suitable place, where, enveloped 
in a clay or mud covering, the unfortunate spider, with a 
number of the eggs of the insect thrust into its body, is 
left to its terrible fate. In due course of time the larvie 
hatch and feed upon the helpless victim. 
Probably many of my readers have noticed the little 
lumps or patches of dried mud in nooks and corners of: 
verandas, and at the bottom of shingles and clapboards 
on barns and houses, and perhaps have broken them open 
and found the paralyzed spiders being eaten alive by the ' 
newly hatched larvre. 
That the wasps should know the exact degree and nian-i 
ner in which the spiders must be stung is remarkable. 
Darwin, in commenting on this fact, says : 
"Certain wasp-like insects, which construct in the cor- 
ners of the veranda clay cells for their larvje, are very, 
numerous in the neighborhood of Rio. These cells they' 
The Tarantula Killer. 
stuff fitll of half-dead spiders and caterpillars, which thejj 
seem wonderfully to know how to sting to that degree as 
to leave them paralyzed, but alive, until their eggs ar« 
hatched, and the larvse feed on the horrid mass of power^ 
less, half-killed victims." 
It has been stated that nearly every type of spider has 
its special enemy among the mud daubers. Probably th« 
largest of these is the tarantula killer (Pompilus for- 
mosus), as it is called everywhere in Texas. This insecti 
which is over two inches in length, is armed with a for- 
midable sting, with which it attacks its terrible foe, one 
thrust being sufficient to paralyze' the great spider, the 
introduction of its venom being "as sCidden as the snap ol 
an electric spark." 
