Strangely enough, the one really dangerous spider on the American
continent is small, obscure, and practically unknown to popular
or journalistic hysteria. Latrodectus mactans is its scientific
name. It is about the size of a large pea, black with a red spot
on the back--a useful danger signal--and spins a small web in
outhouses or around wood-piles. So far as is known, its poison is
the most virulent and powerful, drop for drop, secreted by any
living creature. Cobra virus, in the minute quantity which the
Latrodectus's glands contain, would probably have no appreciable
effect upon man; whereas the tiny spider's venom, in the volume
injected by the cobra's stroke, would slay a herd of elephants.
Were this little-known crawler as large as the common black
hunting spider of our gardens and lawns, its bite would be almost
invariably fatal. Happily, the "red-spot's" fangs, being small
and weak, can with difficulty penetrate the skin, and are able to
inject venom in dangerous quantity only when the bite is
inflicted upon some tender-skinned portion of the body.
Nevertheless, fatalities consequent upon the bite of this insect
are sufficiently well attested to take rank as established
scientific facts.
One of the most detailed comes from an intelligent farmer of
Greensboro, North Carolina. A workman in his employ, while
hauling wood, brushed at something crawling upon his neck and
felt a sharp, stinging sensation. He found a small, black spider
with a red spot. This was at 8.30 A.M. Presently, ten small white
pimples appeared about the bitten spot, though no puncture was
visible and there was no swelling. The pain soon passed, but
returned in three hours and became general, finally settling in
the abdomen and producing violent cramps. At one o'clock the man
had a spasmodic attack. Two hours later he had so far recovered
as to be able to go back to work, for an hour. Then the spasms
took him again; he sank into coma, and died between ten and
eleven o'clock that evening, about fourteen hours after the bite.
At no time were there local symptoms or swelling, other than the
slight eruption, but the neck, left arm, and breast are reported
as having assumed a stonelike hardness.
The same farmer had seen, three years previous, a negro who had
been bitten upon the ankle by a "red-spot" and who suffered from
diminishingly severe spasmodic attacks for three weeks. The white
pimples appeared in this case also. The negro recovered, but the
eruption reappeared for years thereafter whenever he was
overheated.
Recoveries from Latrodectus bite are much more common, in the
records, than deaths. Dr. Corson, of Savannah, Georgia, reports
six cases, characterized by agonizing pains, spasmodic
contractions like those of tetanus, and grave general symptoms.
All recovered. From Anaheim, California, a fatal case is reported
by Dr. Bickford, death occurring twenty hours after the bite.
William A. Ball, of San Bernardino, California, gives a vivid
account of his sensations after being bitten on the groin by a
red-spotted spider, the data being attested by his physician.
Shortly after being bitten, he began to suffer great agony, with
convulsive contractions of the muscles.
"The pains in my hip-joints, chest, and thighs grew rapidly more
violent, until it seemed that the bones in these parts of my body
were being crushed to fragments." He was seriously ill for ten
days.