À
a pity to kill sucli nice little animals, for as a Gaucho said,
while sharpening his knife on the back of one, “ Son tan
mansos” (they are so quiet).
Of reptiles there are many kinds : one snake (a Trigono-
cephalus, or more properly a Cophias), from the size of the
poison channel in its fangs, must be very deadly. Cuvier, in
opposition to some other naturalists, makes this a sub-genus
of the rattlesnake, and intermediate between it and the viper.
In confirmation of this opinion, I observed a fact, which
appears to me very curious and instructive, as showing how
every character, even though it may be in some degree independent
of structure, has a tendency to vary by slow degrees.
The extremity of the tail of this snake is terminated by a
point, which" is very slightly enlarged; and as the animal
glided along, it constantly vibrated the last inch; and this
part striking against the dry grass and brushwood, produced
a rattling noise, which could be distinctly heard at the distance
of six feet. As often as the animal was irritated or
surprised, its tail was shaken ; and the vibrations were extremely
rapid. Even as long as the body retained its irrita-
hihty, a tendency to this habitual movement was evident.
This Trigonocephalus has, therefore, in some respects the
structure of Vipera, with the habits of a Crotalus ; the noise,
however, being produced by a simpler device. The expression
of this snake’s face was hideous and fierce; the pupil
consisted of a vertical slit in a mottled and coppery iris ; the
jaws were broad at the base, and the nose terminated in a
triangular projection. I do not think I ever saw any thing
more ugly, excepting, perhaps, in some of the vampire bats.
I imagine this repulsive aspect originates from the features
being placed in positions, with respect to each other, somewhat
proportional to those of the human face; and thus we
obtain a scale of beauty.
Amongst the Batrachian reptiles, I found only one little
toad, which was most singular from its colour. If we imagine,
first, that it had been steeped in the blackest ink, and
then when drv, allowed to crawl over a board, freshly painted
with the brightest vermilion, so as to colour the soles of
its feet and parts of its stomach, a good idea of its appearance
will be gained. If it is an unnamed species, surely it
ought to be called diabolicus, for it is a fit toad to preach in
the ear of Eve. Instead of being nocturnal in its habits,
as other toads are, and living in damp obscure recesses, it
crawls during the heat of the day aliout the dry sand-hillocks
and arid plains, where not a single drop of water can be
found. It must necessarily depend on the dew for its
moisture; and this probably is absorbed by the skin, for it is
known, that these reptiles possess great powers of cutaneous
absorption. At Maldonado, I found one in a situation
nearly as dry as at Bahia Blanca, and thinking to give it a great
treat, carried it to a pool of water; not only was the little
animal unable to swim, but, I think, without help would soon
have been drowned.
Of lizards there were many kinds, but only one remarkable,
from its habits. It lives on the hare sand near the sea
coast, and from its mottled colour, the brownish scales being
speckled with white, yellowish red, and dirty blue, can hardly
be distinguished from the surrounding surface. When frightened
it attempts to avoid discovery by feigning death, with
outstretched legs, depressed body, and closed e y e s: if further
molested, it buries itself with great quickness in the loose
sand. This lizard, from its flattened body and short legs,
cannot run quickly. It belongs to the genus Ophryessa.
I will here add a few remarks on the hybernation of animals
in this part of South America. When we first arrived
at Bahia Blanca, September 7th, 1832, we thought nature
had granted scarcely a living creature to this sandy and dry
country. By digging, however, in the ground, several insects,
large spiders, and lizards were found in a half torpid
state. On the 15th, a few animals began to appear, and by
the 18th (three days from the equinox), every thing announced
the commencement of spring. The plains were
ornamented by the flowers of a pink wood sorrel, wild peas,
oenothersG, and geraniums; and the birds began to lay their
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