We will now turn to the terrestrial species (A. Demarlii), with a
round tail, and toes without webs. This lizard, instead of being
found like the other on all the islands, is confined to the central
part of the archipelago, namely to Albemarle, James, Barrington,
and Indefatigable islands. To the southward, in Charles, Hood, and
Chatham Islands, and to the northward, in Towers, Bindloes, and
Abingdon, I neither saw nor heard of any. It would appear as if it
had been created in the centre of the archipelago, and thence had
been dispersed only to a certain distance. Some of these lizards
inhabit the high and damp parts of the islands, but they are much
more numerous in the lower and sterile districts near the coast. I
cannot give a more forcible proof of their numbers, than by stating
that when we were left at James Island, we could not for some time
find a spot free from their burrows on which to pitch our single
tent. Like their brothers the sea-kind, they are ugly animals, of a
yellowish orange beneath, and of a brownish-red colour above: from
their low facial angle they have a singularly stupid appearance.
They are, perhaps, of a rather less size than the marine species;
but several of them weighed between ten and fifteen pounds. In
their movements they are lazy and half torpid. When not frightened,
they slowly crawl along with their tails and bellies dragging on
the ground. They often stop, and doze for a minute or two, with
closed eyes and hind legs spread out on the parched soil.
They inhabit burrows which they sometimes make between fragments of
lava, but more generally on level patches of the soft
sandstone-like tuff. The holes do not appear to be very deep, and
they enter the ground at a small angle; so that when walking over
these lizard-warrens, the soil is constantly giving way, much to
the annoyance of the tired walker. This animal, when making its
burrow, works alternately the opposite sides of its body. One front
leg for a short time scratches up the soil, and throws it towards
the hind foot, which is well placed so as to heave it beyond the
mouth of the hole. That side of the body being tired, the other
takes up the task, and so on alternately. I watched one for a long
time, till half its body was buried; I then walked up and pulled it
by the tail; at this it was greatly astonished, and soon shuffled
up to see what was the matter; and then stared me in the face, as
much as to say, "What made you pull my tail?"
They feed by day, and do not wander far from their burrows; if
frightened, they rush to them with a most awkward gait. Except when
running down hill, they cannot move very fast, apparently from the
lateral position of their legs. They are not at all timorous: when
attentively watching any one, they curl their tails, and, raising
themselves on their front legs, nod their heads vertically, with a
quick movement, and try to look very fierce; but in reality they
are not at all so: if one just stamps on the ground, down go their
tails, and off they shuffle as quickly as they can. I have
frequently observed small fly-eating lizards, when watching
anything, nod their heads in precisely the same manner; but I do
not at all know for what purpose. If this Amblyrhynchus is held and
plagued with a stick, it will bite it very severely; but I caught
many by the tail, and they never tried to bite me. If two are
placed on the ground and held together, they will fight, and bite
each other till blood is drawn.
The individuals, and they are the greater number, which inhabit the
lower country, can scarcely taste a drop of water throughout the
year; but they consume much of the succulent cactus, the branches
of which are occasionally broken off by the wind. I several times
threw a piece to two or three of them when together; and it was
amusing enough to see them trying to seize and carry it away in
their mouths, like so many hungry dogs with a bone. They eat very
deliberately, but do not chew their food. The little birds are
aware how harmless these creatures are: I have seen one of the
thick-billed finches picking at one end of a piece of cactus (which
is much relished by all the animals of the lower region), whilst a
lizard was eating at the other end; and afterwards the little bird
with the utmost indifference hopped on the back of the reptile.
I opened the stomachs of several, and found them full of vegetable
fibres and leaves of different trees, especially of an acacia. In
the upper region they live chiefly on the acid and astringent
berries of the guayavita, under which trees I have seen these
lizards and the huge tortoises feeding together. To obtain the
acacia-leaves they crawl up the low stunted trees; and it is not
uncommon to see a pair quietly browsing, whilst seated on a branch
several feet above the ground. These lizards, when cooked, yield a
white meat, which is liked by those whose stomachs soar above all
prejudices. Humboldt has remarked that in intertropical South
America all lizards which inhabit dry regions are esteemed
delicacies for the table. The inhabitants state that those which
inhabit the upper damp parts drink water, but that the others do
not, like the tortoises, travel up for it from the lower sterile
country. At the time of our visit, the females had within their
bodies numerous, large, elongated eggs, which they lay in their
burrows: the inhabitants seek them for food.
These two species of Amblyrhynchus agree, as I have already stated,
in their general structure, and in many of their habits. Neither
have that rapid movement, so characteristic of the genera Lacerta
and Iguana. They are both herbivorous, although the kind of
vegetation on which they feed is so very different. Mr. Bell has
given the name to the genus from the shortness of the snout:
indeed, the form of the mouth may almost be compared to that of the
tortoise: one is led to suppose that this is an adaptation to their
herbivorous appetites. It is very interesting thus to find a
well-characterised genus, having its marine and terrestrial
species, belonging to so confined a portion of the world. The
aquatic species is by far the most remarkable, because it is the
only existing lizard which lives on marine vegetable productions.
As I at first observed, these islands are not so remarkable for the
number of the species of reptiles, as for that of the individuals,
when we remember the well-beaten paths made by the thousands of
huge tortoises--the many turtles--the great warrens of the
terrestrial Amblyrhynchus--and the groups of the marine species
basking on the coast-rocks of every island--we must admit that
there is no other quarter of the world where this Order replaces
the herbivorous mammalia in so extraordinary a manner. The
geologist on hearing this will probably refer back in his mind to
the Secondary epochs, when lizards, some herbivorous, some
carnivorous, and of dimensions comparable only with our existing
whales, swarmed on the land and in the sea. It is, therefore,
worthy of his observation that this archipelago, instead of
possessing a humid climate and rank vegetation, cannot be
considered otherwise than extremely arid, and, for an equatorial
region, remarkably temperate.
