[Illustration: A skeleton of a megatherium, mounted as if for display
in a museum.]
Our conceptions of the plan of Nature must, to say the least, be ever
imperfect: perhaps we do not err in supposing that it is the design of
Providence to fill all space with life and enjoyment. We may look in two
directions at her works; by the assistance of the microscope we find
everywhere minute vegetable and animal productions:--rising from the
contemplation of these, we turn to that luxuriant vegetation, and to
those huge animals which, according to the economy and fabric of the
animal body, exhibit the largest possible dimensions. Of these it would
appear that many have yielded their abode to man, and are now extinct.
In the great plains of South America, and more especially behind Buenos
Ayres, in that flat country which is washed by the Parana and its
tributaries, there are found the remains of enormous animals. Their
bones lie sunk in the mud, or alluvial soil; and sometimes, during a
very dry season, when the waters are low, they appear standing up above
the surface like trunks of trees, or _snags_ as they are called in
America. Such are the bones lately brought to London by the very
meritorious exertions of Mr. Parish.
The inhabitants of a remote district saw the pelvis of the animal which
we are going to describe, appearing above the water, and throwing a
lasso, or cord, over it, they drew it ashore. The pelvis is the circle
of bones which extends from haunch to haunch; and we may form some
conception of its size, both from the manner in which it was found, and
from the lively remark of Professor Buckland, on seeing this portion of
the skeleton--that two of the largest members of the Geological Society
might pass through its circle. When we put our hands upon our haunches,
we rest them upon the wings of the pelvis: now if we extend our arms to
the utmost, we have an exact measure of the breadth of the bones of
which we are speaking, for it measures across from five to six feet.
This part of the skeleton was brought to the authorities at Buenos
Ayres; from whom Mr. Parish had interest to obtain it: after which, he
sent some hundred miles into the country; had the bottom of the river
sounded and dragged for the remainder of the bones; and, finally, had
that part of the water dammed off, so as to obtain the skull, the
vertebræ of the spine and of the tail, the bones of the hinder
extremity, and the shoulder bone. This skeleton, imperfect as it is,
proves to be, not the mastodon, or fossil animal of the Ohio, but the
great fossil animal of Paraguay, the last discovered of the extinct
species, and called megatherium by Cuvier, from two Greek words which
signify the _great monster_.
An imperfect skeleton of this animal is in the Royal Cabinet of Natural
History at Madrid; and it is singular enough that what is wanting in
those bones is supplied in the present. Some doubts were entertained,
for example, whether the pelvis made a complete circle, for this part,
in the Madrid skeleton, was broken off in front; the sagacious Cuvier
presumed that it did; and our specimen proves it.
Examining these bones, putting them together, and comparing them with
the drawings of Joseph Garrega, Madrid, 1796, and of Dr. Pander and Dr.
D’Alton, of Bonn, 1821, we may venture upon some speculations concerning
them. The hinder parts of this animal must have been of great magnitude
and strength compared with the anterior part. Anatomists know, from the
inspection of the bones, what was the condition of the muscles; for the
processes by which they are acted upon are ever strong and projecting,
when the muscles are powerful. The processes of the pelvis show what
large and strong muscles must have operated upon the thigh bone; and the
thigh bone itself is an extraordinary object. It is two feet five inches
in length; is three feet four inches round its thickest, and two feet
two inches round its smallest, part; it is thus twice or three times the
thickness of the thigh bone of the elephant. It is of very great
solidity, and the ridges or processes which stand out from it, imply
that the muscles were of extraordinary power. The bones of the leg, the
tibia and fibula, which are separate in other animals, are here short,
thick, and united into one compact bone. The calcaneum, or heel bone,
projects far, being more than a foot in length, and thus it gives a
powerful lever to the muscles that are attached to it. And the bones of
the toes are, indeed, very curious; exhibiting to the comparative
anatomist that structure which is adapted for the attachment of long and
clumsy claws--but neither like the split hoof of the ruminating animals,
nor the retractile claws of the feline, or cat tribe, and resembling
more the tardigrade class, or sloths. Some have estimated the foot to be
upwards of four feet in length, and to be a foot in breadth.
A most ingenious member of the Geological Society, in his observations
upon this subject, conceived that this great strength was given to the
hinder extremities of the animal, that it might the better stand upon
three feet, and scratch with the fore foot that was free. We should have
the more willingly assented to this idea had the hind foot been
obviously calculated for standing upon; but the processes of the bones,
and the formation of the toes, seem to indicate that this limb was to be
more actively employed. Why not suppose that it dug like such animals as
we see employed in digging?--they work with their fore feet, and, after
a certain accumulation, make more desperate exertions with their hind
feet, to clear away the encumbrance. On the whole, the extremities of
this animal must have been short compared with his length, and the
breadth of his haunches; for his height is not estimated at more than
seven feet. As we have said, the processes of the bones imply great
muscular strength, and, probably, activity,--such activity as we see in
the motions of the armadillo.
Nothing is more surprising than the smallness of the head in this
animal: indeed we could not have believed that the head belonged to
these enormous bones, had not Mr. Cliff put the vertebræ together, and
did we not see that those of the neck corresponded with each other; and
that the anterior vertebra of all, the atlas, fitted exactly into the
articulating processes of the skull. This part is imperfect, but happily
the teeth and a portion of the jaw are here. The teeth are most singular
in their structure. There are no incisors or front teeth. Probably the
animal had a projecting snout, like the tapir in the Zoological Gardens.
It certainly had not a trunk like the elephant; because the length of
the neck, as shown by the vertebræ, enabled it to reach the ground with
the mouth: and neither the form of the bones of the face, nor the holes
through which the nerves pass, indicate the attachment of such an organ
as the trunk. The teeth are seated in the back part of the jaw; their
ground surfaces enter into one another with extraordinary exactness; and
the enamel is so placed that they are worn in a manner quite peculiar.
They are unlike the teeth of the lion or of the tiger; they obviously
suffered great attrition: and are provided against a rapid wasting by
the mode of their growth, which resembles that of the front teeth of
animals which gnaw--the rodentia. The projecting incisor teeth of the
beaver, for example, cut like an adze, but they necessarily suffer from
the attrition; to provide against which they grow at their roots, and
advance forwards in proportion as they waste on their exposed surfaces.
These teeth of the megatherium, although in the usual place of grinders,
have the provision for growing at the fangs, whilst they waste on their
crowns; which implies that they were used in cutting vegetables, and,
probably, the roots dug out of the earth. From the processes of the
scapula, or shoulder-blade, we see that this animal had a clavicle, or
collar-bone, and that the radius and ulna had free rotatory motion: the
marks upon the humerus, too, show that the muscles which roll the
wrist-joint were powerful: now these, with the adaptation in the form of
the toes for long and strong claws, lead us to believe that the animal
turned out the earth like the mole, and was in structure something
between the sloth and the ant-eater. Altogether, it would appear that he
dug and searched for roots, and lived on vegetables.
There is another fact important to our speculations on the habits of
this animal; there has been brought home from the same districts, and
found along with bones similar to these, though remotely placed from the
present specimen, a cover like the shell of the armadillo, but of a size
like a great brewer’s boiler, and studded with tubercles, like the nails
upon a prison-door. If this shell covered the animal, for what purpose
of defence could it be? An ingenious geologist conceived that the animal
had the power of flinging up the soil in such masses, that, in
descending, it required a protection to its back. This conjecture will
hardly be satisfactory; and yet to suppose that such a creature,
possessed of such dimensions, could have a formidable enemy, and that it
required the protection of a defensive armour, like the armadillo, is
perhaps equally extravagant.
According to the methods of the naturalists, from the circumstance of
this animal wanting the front teeth, we should class it with the
_Edentés_ of Cuvier, and, following that author, place it along with the
megalonyx (having _large claws_). This latter animal, also extinct,
President Jefferson described as a great lion, higher in limbs than our
largest ox, and the enemy of the grand mastodon, thereby presenting a
terrific idea of the ancient world. But Cuvier, by his knowledge of
anatomy, proved it to have been a vegetable feeder, and to be properly
classed with the tardigrade animals, a harmless race.
This specimen of the megatherium, in its magnificent ruins, must give
activity to the fancy. It is said that there is nothing interesting in
antiquarian research, but as it is associated with man,--with human
action or suffering. But here are remains which carry the mind back to
the most remote times; not into the contemplation of the ages of
mankind, but to the earlier condition of the globe, when it was
undergoing a succession of changes, which were, at length, to suit it
for the abode of the human race.
The condition of a part of these bones may convey an idea of the plains
where they are found. Some of them are nearly consumed by fire; the
natives using them for setting their kettles on when cooking. To
understand how they should be applied for such uses, we must recollect
that there is no stone to resist the fire; and that there is nothing but
mud and vegetable productions for many hundred miles around where these
bones were discovered.
The wood-cut of the megatherium at the head of this notice is copied
from a plate in the great work of Cuvier on Fossil Bones, which
representation is from the specimen in Madrid.
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