Venomous as is the bite of the rattlesnake, and abounding as it does in
all parts of the continent, it is less dreaded than many other serpents.
It is, in the first place, very sluggish in its habits; and it is
happily compelled to bear about it an instrument which gives notice of
its approach and intention of biting. The South American rattlesnake--
the Boaquira crotalus horridus--has the rattle placed at the end of the
tail. It consists of several dry, hard, bony processes, so shaped that
the tip of each upper bone runs within two of the bones below it. By
this means they have not only a movable coherence, but also make a
multiplied sound, each bone hitting against the others at the same time.
The rattle is placed with the broad end perpendicular to the body, the
first joint being fastened to the last vertebra of the tail by means of
a thick muscle under it, as well as by the membranes which unite it to
the skin. Indeed, an idea of this curious structure may be formed by
placing a number of thimbles one within the other. These bony rings
increase in number with the age of the animal; and they are generally
found with from five to fourteen. The sound produced has been compared
to that of knife-grinding. It cannot be heard at a distance, and in
rainy weather is almost inaudible.
The effects of the bite vary according to the season of the year;
indeed, at times it will seldom strike a foe, and the venom is
comparatively mild in its effects. At other times the poison is of
deadly intensity, and, should a large vein be bitten, the victim
speedily dies.
Waterton describes handling a number of rattlesnakes--removing them from
one apartment to the other--with his hands alone. They hissed and
rattled when he meddled with them, but did not offer to bite him.
Possibly this might have occurred during the time when they were
sluggish, and their venom less deadly.
The little peccary is a great enemy of the rattlesnake, as it is of all
other serpents, and ordinary hogs destroy it easily without suffering
from its bite; so that as man makes progress through the country and
introduces these animals, rattlesnakes speedily disappear.
Although the fascinating powers of the rattlesnake have been doubted, it
seems probable that small birds and animals are frequently attracted
when they catch sight of it coiled up on the ground below the branches
on which they are posted--and, if not fascinated, fall through terror
into its open jaws; or it may be that, influenced by the same
overpowering impulse which induces human beings to rush into danger, the
animal or bird, on beholding its deadly enemy, approaches it against its
own will, and is drawn nearer and nearer, till it either falls into the
deadly fangs, or comes near enough to be entrapped.
Bates was one day in a forest with a little dog, which ran into a
thicket and made a dead-set on a large snake whose head was raised above
the herbage. The serpent reared its tail slightly in a horizontal
position, and shook its terrible rattle. It was some minutes before he
could get the dog away. This shows how slow the reptile is to make the
fatal spring.
On another occasion, he heard above his head, as it seemed, a pattering
noise, when the wind, which had been blowing, lulling for a few moments,
he discovered that it proceeded from the ground, and, turning his head,
was startled by a sudden plunge, a heavy gliding motion betraying a
large rattlesnake making off almost beneath his feet.