ORDER EDENTATA, OR BRUTA (ANIMALS WITHOUT FRONT TEETH).
CHAPTER I.
TARDIGRADA, OR SLOTHS.
The South American Forests—Discovery of the Sloth—How it derived its Name—Peculiarities of Dentition—Food—Fore Limbs and Fingers—Hind Limbs and Heel—Other Modifications of Structure—Kinds of Sloth—Waterton’s Captive Sloth—Habits of the Animal—Burchell’s Tame Sloths—Manner of Climbing Trees—Disposition—Activity among Trees—Naturalists’ Debate about Anatomy—Probable Conclusion regarding it—Skeleton—Vertebræ—the Rudimentary Tail—Most Distinctive Skeletal Characters—Arm, Wrist, Hand, Fingers, Claws—Mode of Walking—Great Utility of the Claws—Face of Sloth—Skull—Teeth—Classification—[TARDIGRADA]—[BRADIPODIDÆ]—[Genus BRADYPUS]—Characteristics—[Genus ARCTOPITHECUS]—Characteristics—[CHOLŒPODIDÆ]—[THE COLLARED SLOTH]—Description—Skull Bones—Habits—Circulation of the Blood—Rete Mirabile—[THE AI]—[THE UNAU]—Appearance—Skull and Teeth—Skeleton—Interesting Anatomical Features—Stomach—[HOFFMANN’S SLOTH]—Description—Habits
WHEN the dense forests of the northern parts of South America were first explored by Europeans, it was observed that active Spider Monkeys, Howlers, and their Quadrumanous allies, were not the only climbing animals which frequented the trees. For every now and then, hunters came in sight of creatures about the size of a large Monkey, but whose sluggish movements, long hair, short heads, small ears and tail, and very long claws, enabled them to be distinguished at once from their very lively companions. It was noticed that these new creatures, instead of climbing quickly and swinging from branch to branch and running along the boughs, moved very slowly, by hanging head and body downwards and grasping the branches with their long claws. During the daytime, these quiet animals were constantly found asleep, huddled up in the fork of a branch, and looking like great balls of tow, or else hanging by two legs, the rest of the body being curled up. Now and then, one was seen at the foot of a tree, and it appeared to run along the ground with great difficulty; for the arms were so long that it walked on the elbows, and the hind feet were turned in, so that it supported itself on the sides of its great hind claws. Naturally, the animal took its time in moving, and as it was never seen to be lively, it received the name of Sloth. Interesting from being so different in its habits from other arboreal animals, it became much more so, to naturalists, when its remarkable construction was ascertained; but still the hairy creature with a short face, small head, long neck, hardly any tail, and very long front limbs, retained its popular name.
A very slight examination of one of the Sloths showed that it had no front teeth, that is to say, neither incisors nor true canine teeth, and that the hinder teeth—the false and true molars—were not like those of any other mammal. The back teeth, few in number, have since been ascertained to be exceptionally simple in their structure, and evidently the masticating process is very simple. But when it was noticed that the Sloth fed upon leaves and young twigs, the absence of the necessity for more elaborate teeth was acknowledged. Then it was observed that they had very long arms, or rather fore limbs, for the fore-arm bones and the humerus are all unusually long, and also that they had great power of movement. Moreover, it was seen that the fingers were reduced to three in number in some kinds, and to two in others, and that they were furnished with long and strong claws, which did not interfere with a great amount of mobility in the wrist. The length of limb, the mobility of the wrist, and the great claws, enable the Sloth to bring the leaves to its mouth, to hang on, and to walk, as it were, beneath the branches. An examination of the hind limbs showed that they were shorter than the others, and always furnished, in all kinds of Sloths, with three great claws. But the ankle seemed to be turned in, as if there was a state of “club-foot.” This condition would enable the toes to clasp a bough without effort, but it would prevent the sole from being placed flat on the ground. As the knowledge of the anatomy of these constant tree-livers progressed, other modifications of structure, equally important in relation to the peculiar arboreal life and food, were gradually discovered. For instance, a remarkable flexibility of the neck, produced by the peculiar arrangement of the vertebræ; a rete mirabile, to a certain extent, in the limbs, resembling somewhat that in the Lemurs (Vol. I., pages 213, 245), and a complicated stomach suited for the digestion of leaves, and foreshadowing that of the Ruminants.
Two different kinds of Sloths were described in the first instance, and subsequently, several others. The first kinds known were the Ai, a Sloth with three claws on the fore limb, and the Two-toed Sloth, with two claws on the fore limb. The Ai was called Bradypus tridactylus, and the other the Unau, or Bradypus didactylus, names which have been changed somewhat, as will be seen further on.
Sloths are caught without much difficulty, and their habits, in captivity, have been observed in South America, and also after their removal to Europe. Waterton writes[56] on the subject:—
“Some years ago I kept a Sloth for several months. I often took him out of the house and placed him on the ground, in order to have an opportunity of observing his motions. If the ground were rough he would pull himself forward by means of his fore-legs, at a pretty good pace, and he invariably shaped his course towards the nearest tree; but if I put him upon a smooth and well-trodden part of the road, he appeared to be in trouble and distress. His favourite abode was the back of a chair, and often getting all his legs in a line upon the topmost part of it, he would hang there for hours together. The Sloth, in its wild state, spends its whole life upon trees, not upon the branches, but under them; he moves suspended from the branch, he rests suspended from it, and he sleeps suspended from it; hence his seemingly bungled conformation is at once accounted for. One day, crossing the Essequibo, I saw a large Two-toed Sloth on the ground upon the bank, and although the trees were not twenty yards from him, he could not make his way through the sand in time enough to make his escape before we landed. He threw himself on his back and defended himself with his fore-legs. I took a long stick and held it for him to hook on, and then conveyed him to a high and stately Mora. He ascended with wonderful rapidity, and in about a minute he was almost at the top of the tree. He now went off in a side direction, and caught hold of the branch of a neighbouring tree, and then proceeded towards the heart of the forest.”
At Santos, in Brazil, in 1826, Mr. Burchell kept a tame Sloth, a Bradypus tridactylus, which at the end of two months pined and died. It fed exclusively on the buds and leaves of a species of Cecropia, a tree having a slender stem of thirty or forty feet long, with horizontal branches, hollow internally, and naked, except at the extremities. It ate only the young shoots and terminal buds of the unexpanded leaves, rejecting the old leaves on the boughs, which were brought to it daily. It was always perfectly silent, and its countenance and manners were most expressive of melancholy. It fed by day, and slept much; being kept in a room, it sat upright upon its short tail, embracing the legs of a chair with its arms and legs.
When resident at Para, near the mouth of the Amazons, Mr. Burchell also kept two full-grown Sloths, and a young one of a three-toed species (not Bradypus tridactylus, but of nearly similar form and habits), in a garden enclosed with strong stockades. They were kept tied up to the pillars of a verandah, to prevent their escape. Against these pillars they always placed themselves in an erect position, embracing the pillar with all four legs; when not tied to the verandah, they got up into trees in the garden. They slept both by day and night, always fixing their arms round something or other. Their food, consisting of branches, was brought to them in the verandah. They appeared extremely stupid, and would never come to the food. They would eat no leaves but those of the Cecropia.
They did not mount very large trees, and they ascended with their breasts pressing the trunk of the tree, advancing the hind-leg beyond the fore-leg. On the ground, they could neither stand nor walk, but lay sprawling on their belly, and dragged, or rather warped, themselves along, laying hold of a bunch of grass or stone with their three claws, which operated like grappling-irons, or, rather, pincers. All these died in a month or two. In their wild state they are seldom seen, from their colour mingling with the grey foliage of the trees, and from their being so extremely quiet and slow. The tame Sloths never willingly remained on the ground, except to pass from one tree to another. All the movements of the animal are slow. It moves its claws slowly. In eating it chews slowly; it also climbs slowly. The moisture of the leaves it eats suffices it for drink, without descending to obtain water. None of those kept by Mr. Burchell were ever seen to drink. The full-grown animals were never heard to utter any sound, but the young one occasionally, though rarely, gave a short cry or whistling squeak, of a single note.
They showed no indication of fear, and seemed to give attention only with their eyes. They took no notice of the boy who often carried them across the garden to their place in the verandah, with their long arms sprawling; the only objects of their regard were trees. They fight on their backs, and grapple their enemy to strangulation. The use of the long wool that covers the body, and even the face, seems to be to guard them from the annoyance of insects. Possibly it may preserve them from the attacks of Snakes, which are, doubtless, their greatest enemies.
The Sloth spends nearly the whole of its life in the trees, and travels along the branches body downwards. It rarely comes to the ground, on which it walks with difficulty, and it occasionally takes to the water and swims. It looks slothful enough when asleep, for it then resembles a bunch of rough hair, and a jumble of limbs close together, hanging to a branch; but when awake, it is industrious in its search for nice twigs and leaves, and moves along the under side of the branches of the trees with some activity. It seizes the ends of adjoining branches, clinging to the leafy mass, and moves from tree to tree quickly enough, when it is requisite, and it has a very singular power of moving the head and neck backwards in seeking food. When the atmosphere is still, the Sloth keeps to its tree, feeding on the leaves and twigs, but when there is wind, and the branches of neighbouring trees come in contact, the opportunity is seized, and the animal moves along the forest, under the shady cover of the boughs. The Indians have a saying that “when the wind blows the Sloths begin to crawl,” and the reason is thus evident enough—the animal cannot jump, but it can hang, swing, and crawl suspended. Mr. Waterton states, however, that “the Sloth travels at a good round pace, and were you to see him passing from tree to tree you would never think of calling him a Sloth. Being born up in a tree, living amongst the branches, feeding on leaves, and finally dying amidst the foliage, and enjoying life as much as any other animal, its structure and conformation are, of course, admirably suited for this arboreal existence. Its power of grasp is great, and is assisted by the great bent claws as it hangs by its feet when asleep, and also often when it is dead. One which was much frightened by being taken from the forest had a pole placed near it at a little distance from the ground, on two supports. It clung directly to the pole and hung on. A Dog was then made to attack the Sloth, which seized it in its long claws, and did not let go until the enemy died.”
Leading thus a very unusual kind of life, up amongst the dense foliage, and having some very unusual peculiarities of construction, much debate occurred many years since regarding the general conformation as well as the special anatomy of the Sloths. One school of anatomists considered the Sloths incomplete and abnormal animals, moving with “pain” on the ground, and another regarded their unusual and peculiar anatomy as singularly beneficent.
But whilst it is perfectly evident that the long limbs and their joints, and the peculiar turning in of the ankles, and the structure of the clawed hands and feet, are all admirably adapted for the peculiar life which the animal leads, it appears to be consistent with anatomical reasoning to believe that the Sloth is an instance of retrograde development; that, in fact, the peculiar formation of the skull, neck, wrists, and ankles, is the result of the laws of disuse and adaptation operating on ancestral animals, which once had their anatomy more consistent with a perfect mammalian type.
SKELETON OF THE SLOTH.
When the Sloths were first carefully watched and studied, their length of neck and their ability to turn the head, so as to look at a person standing directly behind or beneath them, without swerving the body, struck Mr. Burchell especially. This curious peculiarity led to a careful examination of the skeleton of the different kinds, and much discussion followed, for it was found that in the Sloth examined (the Three-clawed Ai) there were more neck bones (vertebræ of the cervical region) than in other Mammalia. Instead of the common number of seven neck bones, there were nine. This elongation of the neck of course permitted a greater amount of twisting than could occur in an animal with fewer neck bones. But there are other reasons why the head can be so much twisted round, for the spines on the neck bones are small, and the joint between the skull and the first vertebra is so fashioned that this remarkable motion is possible. There was a great deal of discussion about the extra neck bones, and as the last two had rib-like projections from their sides, some anatomists considered them to belong to the true rib-bearing vertebræ, or those of the back (the dorsal). But when the other Sloths were examined it was found that the number of the bones of the neck in all the two-fingered kinds was not as great as in other animals. There are only six neck vertebra in one well-known species (Cholœpus Hoffmanni, for instance), whilst there are seven in another two-toed Sloth.
Eating largely and of bulky substances, the Sloths require a large digestive cavity, and the ribs are numerous, and the body is long and broad. There is much variation, however, in the number of the back bones in the dorsal and lumbar regions. Thus in the Ai there are sixteen dorsal and three lumbar vertebræ, whilst in the Two-fingered Sloth there may be twenty-three or twenty-four dorsal bones, and two, three, or four lumbar vertebræ. The ribs are close together and are broad. As the hind limbs require strong muscles, for the animal hangs on by them whilst it is feeding itself with the fore hands, the pelvis is large and is strengthened by having the hip and haunch bones (ilia and ischia) united to the conjoined sacral vertebræ, which may be six, seven, or eight in number. Moreover, all the strength of the pelvis is behind, the fore part or pubic bones being slender and united in front.
Some small tail bones exist, for that organ is rudimentary in all the Sloths, there being a stump in the Ai, and eleven very small bones; but in the Two-fingered Sloths the tail is not visible, and there are four little ossicles. There are no long and very prominent spines to any of the back bones, and the whole bony column of the spine is readily curved and bent. The animals so constantly bring the hands and feet close together, when hanging, that a ready bending of the spine is absolutely necessary. Moreover, in sleeping they often rest in the fork of a tree, or on a branch, and place the head between the hind legs, rolling the body up as it were in a ball, and this is facilitated by the peculiar construction of the long chain of back bones with small spines.
The most distinctive character of the skeleton of the Sloth is the excess of length of the fore limb over the hind one. An examination of the slender bones of the arm shows that they are more solid than those of most Mammals. The arm bone (humerus) has a hole through it in the inner expanded part, just above the elbow (inner condyle), in the Ai; but this is not found in the two-toed kinds. The wrist and hand are long and narrow, and this is produced by the union of some bones which are separate in other Mammalia, and the slight development of others. Thus there are six bones in the wrist instead of eight (the scaphoid and trapezium, and the os magnum and trapezoid have coalesced). In the Ai there are three clawed fingers, and the bones of the thumb and of the little finger are absent, and their corresponding hand bones (metacarpals) are very small, and are joined on to the next, that is, to the metacarpal of the index and third finger.
The three fingers are, moreover, strengthened for their peculiar uses, the first two joints being united, and the tip or last joint being very long, and supporting the claw. Moreover, as the long claws are constantly half closed in the hand, and they are never required to be widely open, the tip of the finger is so made that flexion is possible, but not unclasping widely. The skin comes up to the base of the claws, and encloses the fingers, and the base of each claw is protected by a bony sheath. They form capital hooks; they grasp, and although there is no opposable thumb, they hold the food; and a tame Sloth may be seen holding a carrot very firmly between them and the wrist. In the case of the Unau Sloth, the outer claw is the longer.
BONES OF HAND OF THREE-TOED SLOTH.
The Sloths walk on the outside of the extremities of the fore and hind limbs, and their claws are always curved in, and, as it were, retracted. Consequently, the animal cannot place the soles flat on the ground, and it cannot open its foot-claws to a great extent. This fixing of the claws assists in the clasping and hanging, which are the usual and commonest attitudes. The claws surpass the foot in length, and are so sharp and crooked that they readily seize upon the smallest inequalities in the bark of the trees and branches upon which the animals habitually reside. They and those of the fore limb are no mean weapons of offence and defence, for, situated at the end of long and muscular arms, they can drag, cling, and hold with great tenacity. The thigh bone (femur) of the Sloth is straight, and is thicker and shorter than the arm bone (humerus); it has no ligament to unite it to the joint (no ligamentum teres). On examining the lower bones of the leg (the tibia and fibula), they will be found to be bent, so as to leave a space between them, and they are shorter than the bones of the fore arm. The bones of the ankle joint, are united together immovably—that is to say, the usual bones seen in other Mammalia are there, but are united by bone. Moreover, this union includes the complete and ill-developed feet bones (metatarsals), and the first bones of the second, third, and fourth fingers. One bone is not included in this strange union. It is the astragalus, or the bone immediately jointed with the ends of the bones of the legs. The outer or small bone of the leg (fibula) fits into a pit in the outer part of the upper surface of this bone, and thus prevents any movement of the foot like a twisting outwards, and favours, but does not produce, the usual position of twisting inwards. Moreover, there are two powerful muscles in the front of the leg which are not opposed by others as strong, and they, by their contraction, keep the foot twisted inwards, as in club-foot (the anterior tibial and the long extensor of the great toe).
In the Unau, or Two-fingered Sloth, there is the same general arrangement of the bones and muscles, with some important differences, which result in there being a greater amount of bending and extending of the foot, although the foot rests on its outer edge.
A Sloth’s face is short, and there is a broad snub nose, with round nostrils, which are widely open. The cheeks become wide suddenly, and the forehead slopes rapidly backwards, the eyes being wide apart and small, but looking forwards. The head is small and round, and as it is covered with hair behind, it cannot be distinguished well from the upper part of the back of the neck. The expression of the face is always the same, and the method of masticating and eating is disagreeable to observe. The animal having no front teeth, and moving its jaws usually only upwards and downwards, and not from side to side, places the morsel, such as lettuce leaf or carrot, well into its mouth, and chews at it, dragging out the food every now and then, when it is covered with moisture. On examining the skull, the short cut off or truncated appearance of the face is very evident, and it will be observed that the teeth are wanting in the front bones of the face (the pre-maxillaries), and that only the palatal part of these bones exists. The lower jaw is strongly jointed to the upper, and the back part is large: there are teeth at the sides, but there are none in the front part of it. A very singular-looking cheek bone (zygoma) exists on either side. It is not attached behind to the ear bone, so as to cover the jaw muscles, but it has two processes behind—an upper and a lower—which differ in shape and size according to the species. The central bone of the nose does not reach to the nasal outlet, and there is a system of air-cavities which is continued from the nose into the forehead bone. In some kinds, the lower jaw ends abruptly in front, as in the Ai; but in the Unau Sloths it is slightly angular, and projects.
The back teeth of the Sloths are very simple, and consist of three structures, called vaso-dentine, hard dentine, and cement, there being no proper enamel. The vaso-dentine is a kind of bony substance in the centre of the tooth, in which there are the passages and tubes of blood-vessels. The dentine is outside this, and consists of more earthy particles than the vaso-dentine, and of fewer tubes; it is all the denser and more resistant. Wearing away more slowly than the vaso-dentine, it forms a ridge which grinds easily. The cement is a kind of bony structure on the outside of the tooth. The teeth of the Sloth continue to grow from below as they are worn above, and there is no entire milk set which are replaced by those of a permanent kind.
SKULL OF SLOTH.[57]
(From the Proceedings of the Zoological Society.)
The term Sloth is commonly applied to all the kinds of animals whose general shape and habits have just been noticed. It is evident, however, that this union of several species under one term is not correct in zoology, and it is necessary to distinguish them by peculiarities which are permanent. A very ready method of distinction is to separate the Sloths into two families, one containing those which have three claws on the fore limbs and the same number on the hind limbs, and the second including those which have only two claws on the fore feet and three on the hinder.
The first family is called the BRADYPODIDÆ, from βραδύς (slow), and πούς (foot), and the second CHOLŒPODIDÆ, from χωλός (halting, lame), and πούς (foot), and both are included in the group TARDIGRADA, or slow-moving Edentata.
The BRADYPODIDÆ include two genera, but many naturalists only acknowledge one. The first is Bradypus. This includes the Sloths with three-clawed fingers on the fore limbs, whose males and females are alike in their fur, and which have the cheek bone (malar bone) with two processes. The upper one is long and dilated at the end, and the lower is long and triangular, and neither of the processes reaches the ear bone. There are in these Sloths, when full grown, five molar teeth on each side in both jaws, and the first is very short. There are two mammæ on the chest.
The second genus is Arctopithecus (Gray), and it contains species which have the males and females dissimilar in their colour and ornamentation, and the malar bone has a thin and narrow upper process.
The second family of the Sloths (the CHOLŒPODIDÆ) contains but one genus, Cholœpus (the Unau), whose species have two claws on the fore limbs and three on the hind ones. The front of the lower jaw is stuck out, and not cut short, and the first molar teeth are long.
The genus Bradypus probably contains several species, but it is only necessary to mention one, which is called
THE COLLARED SLOTH, OR THE HAIRY SLOTH.[58]
This Sloth lives in the densest forests of Brazil, Peru, and Para, and is found not far from Rio Janeiro.
It is a kind of the Three-clawed Sloths, in which there is little or no difference between the fur of the males and females. The neck is surrounded by a large collar of long black hair, and underneath this is a fur of a dark-brown colour. The face is naked, and is of a black colour, and the hair of the body is not very flattened, but is withered-looking to a certain extent. The forehead, temples, chin, throat, and breast are covered with reddish or rust-coloured hair, slightly grizzled. On the crown of the head it is long and yellow, and pale orange on the rest of the body. This Sloth produces one at a birth.
The lower jaw has a kind of blunted lobe in front, and the angle of this jaw is broad, triangular, with a rounded lower edge, and it projects backwards beyond the joint which connects the bone with the skull. The cheek bone has those peculiarities which have already been mentioned. The teeth are peculiar, for the first or foremost grinders are smaller than the others, and the second upper grinder is the largest of all. The first grinder on the lower jaw is broader than the rest, and the hinder are the largest, being also cylindrical.
COLLARED SLOTH. (From Prince Maximilian of Neuwied’s Animals of Brazil.)
It has the general method of living of the Sloths, being perhaps not quite so lively or active as the Unau, and feeds mainly on Cecropia leaves, finishing those of one tree as far as it can before commencing those of another. Like all the Sloths, it has the power of long and sustained muscular action, and can cling on, or grasp, for a very long time without perceptible fatigue, and this gift is associated with a structure of the blood-vessels which supply the muscles, resembling, as we have said, that noticed in some of the Lemurs. The main artery which supplies each of the fore limbs is the axillary, so called from its being found in the armpit or axilla. In quickly-moving animals this vessel reaches into the upper arm, and divides into a few rather large ones lower down, and these give off others, so that a certain quantity of blood is supplied and removed quickly. But in the Sloths the axillary artery divides at once into a number of cylindrical vessels nearly as large as it is, and they are united here and there. These unusual arteries are found in contact with the surface of the muscles, and their branches go in and amongst the muscular bundles. As many as forty-two of these large vessels were counted by Sir A. Carlisle, on the surface of the muscles on the front of the arm, and probably about twenty were inside. These arteries thus carry an immense supply of blood to the muscles, but blood which, although it is finally removed by the veins, does not move very rapidly. In fact, the muscles are turgid with blood. The same arterial structure is seen in the hinder limbs, and the arteries of the thigh form as numerous a set as those of the arm.
AI. (From the Proceedings of the Zoological Society.)
It seems to be in accordance with careful investigation, to state that the species of Sloth called Bradypus tridactylus (the Three-toed Sloth, or Ai) has too large a meaning, and that it really refers to the Collared Sloth, as well as to others which have been placed in the next genus. It is as well to remark here, that although there are three clawed fingers to the fore limb, there are vestiges of two other ones by their side in the form of two rudimentary metacarpal bones.
GENUS ARCTOPITHECUS.—THE AI.[59]
Several kinds of three-clawed Sloths have been called Ai; for instance, the Yellow-throated Ai, and De Blainville’s Ai, and all have been named Bradypus tridactylus. Dr. Gray, however, satisfied himself that the kind which was first described by Cuvier as the Ai, and which is figured in Prince Maximilian of Neuwied’s “Animals of Brazil,” is the same as one which has since been called Arctopithecus Ai, or Arctopithecus flaccidus. The word Ai is taken from the noise made by the animal, and the term flaccidus relates to its long hair. The true Ai inhabits Venezuela and Peru, and has very long flaccid grey hair mottled with white. There is an abundant under-fur of a blackish-brown colour, which has white and black in spots and blotches.
There is a small spot between the shoulders on the back, where the fur is soft and woolly, and a broad, short, blackish streak there, with a white or orange ring around it. The claws are coloured brown. The head has a curiously-cut short and turned-up nose appearance, and is furnished with coarse shaggy hair, disposed on the crown in a diverging manner. The short hair of the face contrasts with the long, shaggy, shrivelled, dry, hay-looking hair of the body. This hair is coarse and flattened at the ends, but it is exceptionally fine at the roots, and it greatly resembles in colour and texture some of the vegetation of the trees on which it lives. The eyes are bright, and are surrounded by a dark ring. Several species of the genus Arctopithecus have been described which live in Guiana, Bolivia, Brazil, Peru, and Venezuela.
SKULL OF AI.
The next genus of the Sloths is represented by
THE TWO-FINGERED SLOTH (THE UNAU).[60]
There are several kinds of Sloths with two “toes,” or rather with two fingers ending in claws on the fore limb, but the differences between the species are not very readily appreciated. They are differences which can be recognised, but it is doubtful whether the possession of dark brown or pale brown hair is sufficient to decide that there are more than one species.
The common Unau Sloth is usually of a darker tint than the others, but there is no doubt that the specimens in museums of all these Sloths vary much in the colour and length of the hair. Thus the hair may be generally dark, and the hairs of the crest on the back of the head may be white, and more or less tinted with bright green; or the hair may be short, of a dark brown colour, paler on the rump, much paler on the head, cheeks, and chin; a band may be across the nose, and the orbits dark brown. Others of the same species have very long hair, of an uniform dark tint, paler on the head and redder beneath, whilst one from Juan de Fuca has short hair, without any indication of a crest. From Brazil there are specimens with long paler hair and a crest. All these specimens, however, have pale whitish claws.
A Unau from Columbia is of a pale and whitey-brown paper colour, darker at the root of the hairs, and it has pale fawn-coloured claws.
In all these animals with different kinds of furs, the two-clawed condition is peculiar to the fore limbs only, for on the hinder there are three claws, and it is to be remarked that the hair and skin unite the fingers and toes close up to the base of the claws. The skull of the Unau is rather projecting in front, and not, as it were, quite cut off close; and there is a great gap in the upper and lower gums in front, the incisor teeth being absent, of course. But at the side of the mouth there is a longish tooth above and below, looking like a canine, but really it is the front molar, which in both jaws and on both sides is longer and larger than the others. The under teeth belonging to the lower molar set are placed behind the corresponding upper ones when the mouth is shut.
The cheek or malar bone is seen, on looking at the skull, to be separated from the ear bone, and to have a forked end posteriorly, the lower part of the fork extending downwards and backwards.
The lower jaw is very straight: it projects a little, in front and behind, where it is jointed with the upper jaw, there is no upright portion or branch, or ascending ramus. The last back tooth is just in front of a curved piece of bone called the coronoid process, the base of which is on a level with the line of the teeth.
This Sloth has seven neck bones (cervical vertebræ), and the last one has a very small and rudimentary rib attached to it on either side. There are no less than twenty-three dorsal vertebræ found to be with ribs. The Unau has a clavicle which is much smaller in the other group. It has no tail. The structure of the ankle joint enables it to turn in, even more than that of the Three-clawed Sloth. As the habits of the Unau Sloth are the same as those with three claws, and all live in the same great district, these anatomical distinctions are very interesting, and relate to their remote ancestors, being hereditary legacies, which are of little or no importance in assisting the creature merely to live. One of the differences between the Sloths is singular. The Unaus have a very remarkably formed stomach, which may be said to be double. The first stomach is large and rounded, but it is contracted behind, and then formed into a kind of conical appendix. This appendix is doubled from left to right, and its cavity has a fold at its opening into the stomach. It forms a special part of the first stomach. Then it is to be noticed, that where the food enters the stomach, or at the opening, which is called the cardia, there is a pouch, looking like a bag at the end of the tube which runs down from the gullet to the stomach. This is the second part of the first stomach: and the third is a tube-like space which connects the cardia with the stomach far away to the left. These three cavities form the first stomach. The second stomach is of a slender form, and is very much smaller than the other. Its walls are thin for the first half of its length, but towards the spot where the gut commences (the pylorus) they are thick and muscular. A small fold occurs midway. There is a fold in the body of the smaller or second stomach, and there is a little hollow there with glands in it, and it is called the appendix to the second stomach.
STOMACH OF SLOTH.
The stomach is thus rather complicated, and its internal mucous membrane is so thrown into folds, and made into hollow spaces, that it occupies much more space than if it were a simple bag. This plan is also well seen in those ruminating animals which, like the Ox, live entirely upon vegetable substances; and it is evident that the diet of the Sloth bears some relation to the complicated stomach.
In the Ai, the appendix to the second stomach is larger than that of the Unau Sloth, and is more complicated.
HOFFMANN’S SLOTH.[61]
This is a Sloth with two clawed fingers on the fore, and with three claws on the hinder extremities. Living specimens are occasionally brought to Europe, especially from Porto Rico, so that its general appearance may now and then be studied at the Zoological Gardens, in the Regent’s Park. If it be looked at there in the day-time, it certainly merits the name of Sloth, for it resembles a bundle of long, light, brown hair, fixed on the top of a bar of wood close to an upright branch, or huddled up in a corner on the ground; but in the morning, and also late in the evening, the creature begins to move slowly, and to look out for the food put for its use on the floor of the den. All the Hoffmann’s Sloths have pale brown hair, whiter at the tips, and a white face, showing a brown band across the nose, extending to a ring round each eye. They have also a long and full crest of hair on the neck, and the hair on the limbs is darker than that of the rest of the animal. Dr. Peters, who discovered this Sloth, examined the skeleton, and found only six vertebræ in the neck, and in this it differs from the Cholœpus just noticed.
When its food, consisting of carrots and lettuce, and bread-and-milk, is put down in the morning it is soon in movement, and enjoys its meal hanging down from a bar with its hind legs, and resting its back on the floor of the cage. It seizes the food between the claws and the long straight palm of the fore-foot, and passes it into its mouth, chewing actively with the molar teeth, especially with the first, which are sharp. It cares little for the spectators, and when it has finished, slowly mounts up into a corner of its little den and settles down to sleep. In the evening it becomes lively, for it is, and, indeed, all Sloths are, nocturnal in habit. The hairless snout, of a light red tint, the absence of “smellers,” the little eyes with a few hairs around them, and the broad forehead, give the animal a curious appearance. The hair is brushed back on the forehead, and comes around the very small ears on to the cheeks, and is whitey-brown, and this same tint is seen over the whole of the back in long slender hairs. But the under hair is light red or red-brown. The long and slender hand, with its two claws, contrasts with the rather bulky upper part of the limbs, and the flesh-coloured palms are very remarkable.
HOFFMANN’S SLOTH.
The whole of the Sloths lead very monotonous lives; their food is ever within their reach, and it is abundant, and they do not appear to have to compete much or at all in the struggle for existence with other animals. Their enemies are Snakes and the Carnivora, but it is evident that they are much more readily preserved by their habits from the latter than from the former. Leading such an uneventful existence, there is no great call upon their nervous energies or intelligence, and these are at a low pitch. The brain consequently is very simple in regard to convolutions, which are few in number and shallow.
CHAPTER II.
THE ANT-EATERS.
[THE CAPE ANT-EATER]—The Cage at “the Zoo”—Appearance of the Animal—Its Prey—The Ant-hills-How the Orycteropus obtains its Food—Place in the Order—Teeth—Skull—Tongue—Interesting Questions concerning the Ant-eater—[THE PANGOLINS, OR SCALY ANT-EATERS]—[THE AFRICAN SCALY ANT-EATERS]—Differences between the Pangolins and Cape Ant-eaters—Their Habitat—Description—[TEMMINCK’S PANGOLIN]—Habits—Food—How it Feeds—Superstitious Regard for it shown by the Natives—Scarcity—Appearance—[THE LONG-TAILED, OR FOUR-FINGERED PANGOLIN]—[THE GREAT MANIS]—[THE ASIATIC SCALY ANT-EATERS]—[THE SHORT-TAILED, OR FIVE-FINGERED PANGOLIN]—The Species of Manis—Skull—Stomach—Claws fitted for Digging—Other Skeletal Peculiarities—[THE AMERICAN ANT-EATERS]—General Appearance—Genera—[THE GREAT ANT-BEAR]—Habits—Diet—How it Procures its Food—Distribution—Mode and Rate of Locomotion—Stupidity—Manner of Assault and Defence—Stories of its Contests with other Animals—Appearance—[THE TAMANDUA]—Description—Where Found—Habits—Odour—[THE TWO-TOED ANT-EATER]—Appearance—Two-clawed Hand—Habits—Von Sach’s Account of his Specimen.
THE CAPE ANT-EATER.[62]—THE AARD-VARK.
IN one of the cages in the house, close to where the Kangaroos are kept, in the Zoological Gardens of London, there is usually a heap of straw to be seen and an empty dish. Outside the cage is placed the name of an animal, “The Cape Ant-eater.” People look and wait, and as neither the animal nor the Ants it eats are to be seen, they go away, supposing that the absence of the last-named insects has caused the destruction of the animal, whose straw alone remains.
But in the evening, and sometimes in the morning, when the food is placed in the cage—not Ants, however—a long pair of stuck-up ears, looking like those of a gigantic Hare with a white skin and little fur, may be seen poked up above the straw; and, soon after, a long white muzzle, with small sharp eyes between it and the long ears, comes into view.
Then a very fat and rather short-bodied animal with a long head and short neck, low fore and large hind quarters, with a bowed back, comes forth, and finally a moderately long fleshy tail is seen. It is very pig-like in the look of its skin, which is light-coloured and has a few hairs on it. Moreover, the snout is somewhat like that of a Pig, but the mouth has a small opening only, and to make the difference between the animals decided, out comes a worm-shaped long tongue covered with mucus. The animal has to content itself with other fare than Ants in England, but it seems to thrive, and as it walks slowly on the flat of its feet and hands to its food, they are seen to be armed with very powerful claws.
In Southern Africa, whence this animal came, it is as rarely seen by ordinary observers as in England, for there it burrows into the earth with its claws, and makes an underground place to live in, and is nocturnal in its habits, sleeping by day.
The Orycteropus, which means digging-up foot, from ὀρύσσω (to dig up), and πούς (foot), is the deadly foe of the Ants of all kinds, and especially of those which, like the White Ants, live in large colonies and build nests.
These nest-building Ants abound in certain districts, but not in the region of the downs or karoos, nor where it is very dry and woody. They choose the country which is covered with a poor and so-called “sour” grass, and there they dig galleries in the ground, fetch earth from far and wide, and erect large rounded mounds of an elliptical figure, and often from three to seven feet in height. Apparently fond of company, the Ants congregate, and these gigantic hills of theirs are often crowded together and occupy the plains, as far as the eye can reach. The nests, or hills, are solidly built, and contain innumerable ants. This is the favourite resort of the Orycteropus, and the insects are his sole food then. Wherever ant-hills are found, there is a good chance of finding one of these Aard-varks, or Innagus, or Ant-Bears, as the Dutch and natives call them, leading a sort of mole-like life. But he is not easy to catch if the stories told be true. It is stated that the long strong flattened claws and short extremities, worked by their strong muscles, enable the animal to burrow in the soft soil as quickly as the hunters can dig, and that in a few minutes it will get out of the way; moreover, its strength is sufficient to resist the efforts of two or three men to drag it out of the hole. But when fairly caught, the Ant-eater does not resist much; it has no front teeth or eye teeth to do any harm with, and it can be killed easily by a blow on the head. The Ant-eater runs slowly, and never moves far from the entrance of its burrow, being seen to do so only at night-time. The burrows are often two feet in diameter and three or four feet deep before they branch off. Night is the time for Ant-eating, for the active and industrious insects are then all at home and within their solid nests. Then the Orycteropus sallies forth, finds a fresh nest, sprawls over it, and scratches a hole in its side, using his strong claws, and then introduces his long snout. Having satisfied himself that there is no danger at hand, the animal protrudes its long slimy tongue into the galleries and body of the nest, and it is at once covered with enraged Ants, which stick to it, and are finally returned with it into the mouth. This goes on over and over again, until the appetite is satisfied; and apparently the diet is excellent, for the Ant-eater is generally fat, and indeed his hams are appreciated as a delicacy for their peculiar flavour, into which that of formic acid is said to enter.
CAPE ANT-EATER.
Although without an armour to its body, and provided with only a thick skin and bristles, the Orycteropus has a great resemblance in many points of its anatomy to the Armadillos of America. It is more closely allied to them than to the other Edentata. It is one of the order of Edentata, for there are no front teeth in the jaws, the incisors and canines being absent. The teeth are found in the back part of the mouth, and there are five on each side and in the upper and lower jaws, or twenty in all; there are also some small teeth which fall out during the growth of the animal. As might be expected from the very simple nature of the diet, the teeth are not at all complicated in their structure. They increase in size from before backwards, the last tooth but one being the largest, and all are peculiar in their minute construction. The first permanent tooth, which may be called a molar, is cylindrical in shape, and consists of a centre of very remarkable substance, for the body of the tooth is composed of a great number of vertical canals placed side by side, and running up the tooth. It was this interesting structure, so different to that of other animals, which led Cuvier to compare the teeth to pieces of cane. Outside this part of the tooth is a hard and more solid substance. When the teeth are unworn, this outer covering covers their top, but as it wears off the tubular appearance is seen, and the ends of the tubes become exposed. The teeth have no fangs like those of such orders of Mammalia as the Carnivora and Insectivora, and they increase in length by growth from below, so that the wear above is continually compensated for. The second tooth resembles the first in its minute construction, but appears like two cylinders fixed together, a longitudinal groove indicating the junction, and this is the appearance presented by most of the others. The hindermost teeth resemble the first molars. The dental number varies according to age, and the presence or absence of the teeth which are not permanent. The jaws, in which the teeth are fixed, are long, and the lower one is low, but there is an ascending back part, or ramus; consequently, the face is long and low. The eye is placed far from the ear, and is small. Its bony case, or orbit, and its surrounding bones, are somewhat remarkable for an Edentate, for there is a lachrymal bone, and the tear canal is open on the bony face. Moreover, the malar bone is united to the ear bone by a complete arch, the zygoma, and the deficiency so remarkable in some other Edentates is thus not observed. The pre-maxillary bones are also to be seen, in front of the face. In this completeness of the bones of the face this animal is a true mammal, but in the nature and extent of the ear bones, the Orycteropus has some resemblance to reptiles and birds.
SKULL OF THE CAPE ANT-EATER.
The tongue is long, narrow, and flat, and can be protruded considerably beyond the mouth, but not so far as those of the other insect-eating Edentata; and in order to keep up a supply of thick mucus, the glands under and at its side, or the sub-maxillary, are very large and active in their functions. The stomach is moderately bulky and not simple, for the portion towards the right has very thick muscular walls, and the rest is thin. The intestine has a blind gut, or cæcum.[63] In fact, the stomach and blind gut might belong to an animal which eats something more bulky and less nutritious than Ants, and would be of use to the creature, did it eat vegetable matters. All these structures, the simple teeth, the tear bones, the size of the ear bones, the Sloth-like teeth, with tubes, however, and the peculiarities about the intestinal canal are, it must be remembered, associated with the life of a purely insectivorous animal. Why has it not the kind of teeth of the Insectivora and their stomach? and why should it combine high and low characters in its skull? These are questions which, when attempted to be answered, show that in the great philosophy of nature causes and effects are not everything, and that the same definite methods of life may be followed by animals very differently constituted.
The claws of the Orycteropus and the limbs are admirably suited for its kind of life. There are five claws on the hind limbs and four on the front, and they are long, slightly curved, flat, and scooped out below. The burrowing is facilitated by the arrangement of the claws as regards length, and they diminish in size from within outwards. There is a collar bone. The foot rests evenly on the ground and not on its outside, and the body is supported either by the whole foot or by the palm surface of the claws. The fore arm can be rotated more or less, and the pronator quadratus[64] muscle enables this necessary action to be carried out. The Orycteropus capensis lives over a wide extent of country in South Africa, in Caffraria, and in the western districts. A closely-allied species lives in Senegal (Orycteropus senegalensis, Less.); and a third is found in Southern Nubia, near the White Nile (Orycteropus æthiopicus, Sund.).
THE PANGOLINS, OR SCALY ANT-EATERS.[65]
THE AFRICAN SCALY ANT-EATERS.
An animal living in the same country, on the same kind of food, and having many of the habits of the Cape Ant-eater, especially as it belongs to the same order of the animal kingdom, might be expected to resemble it in shape and in most of the important parts of its construction. But the comparison between the Ant-eater, just described, and the Scaly Ant-eater, shows that these animals have some very remarkable differences. The Scaly Ant-eater is toothless, and covered with scales.
TEMMINCK’S PANGOLIN.
Formerly, the Scaly Ant-eaters roamed far south in Africa, but now they are rare animals in South Africa, in the west of the continent, and across to Sennaar. They are found in Zanzibar, and as far south as the latitude of Mozambique. They are small animals, of from two to nearly five feet in length, with long tails; and their body, limbs, and tail are covered with numerous large, somewhat angular, and sharp-edged scales, as with armour. The scales overlap each other like tiles, and the free part pointing backwards is bluntly angular or rounded at the tip. When the animal is on its feet walking, they form a very close and impenetrable covering, being doubtless of great use to the creature, for it must trust entirely to its defences, having no weapon of offence. But when the Scaly Ant-eater is alarmed or threatened with danger, or positively attacked, it rolls itself up like a ball, places the snout between the legs, and the tail underneath, and then sticks up its scales, offering their sharp edges to the enemy. There are several kinds of them, and one in particular was noticed by Dr. Smith, the African traveller, and was named after the zoologist Temminck, MANIS TEMMINCKII. He observed that it was rarely seen, but that when it was discovered, instead of burrowing, it did not attempt to escape, but rolled itself up instantly in the shape of a ball, taking especial care of its head, which is the only part unarmoured and likely to be injured. He states that Ants form its chief and favourite food, and that it secures them by extending its projectable tongue into holes which may exist in the habitations of those insects, or which it may itself form. The tongue having made an entry, it is soon covered with a multitude of insects, and as it is well lubricated with saliva, they are held fast, and when a full load is ready, the retracting muscles act on the tongue and the whole is carried back into the mouth, after which the Ants are swallowed. The same traveller accounts for the scarcity of the Scaly Ant-eaters, partly from the disinclination of the natives to discover them for strangers, and partly because they are environed with supernatural gifts in their eyes. They are carefully sought for, by the natives, for their own use and supposed advantage, for they believe the animal to have some influence on cattle, and that certain treatment to which they are exposed produces this. Whenever a specimen is secured by the natives, it is submitted to fire in some cattle-pen, apparently as a burnt offering for the increase of the health and fertility of all cattle which may henceforward enter the fold. “Here,” writes Dr. Smith, “we have another cause for the obliteration of a species. Intolerance of their aggression has wrought up the shepherd or agriculturist to the destruction of some; but in this case, a species is probably dying out under the influence of a superstition.”
FOUR-FINGERED PANGOLIN.
They burrow even in rather hard ground, and feed at night time. It has been noticed that the mother sits upright when enticing the young to suckle.
This Manis has rather a short head, and a wide body, and the tail is as long as the trunk: it is rather less in width near the body, and does not diminish much near the end. In a specimen which is twenty-five inches and a half long, the back of the animal is eight inches across, and the tail at its root is five inches broad. The scales are large, and are in about eleven rows. The body is of a pale yellowish-brown colour, the scales being lightest in tint near their points, and they are often streaked with yellow. Where the scales are wanting the skin is dusky brown. The eyes are reddish-brown, and the muzzle is black. The nails of the fore feet are bent under, so that the animal walks on their upper part. The scales are composed of hairs placed side by side and agglutinated together, and when first formed, and for some little time after, they are soft. They cover the upper part of the fore and hind extremities besides the body, and are striated. This kind lives in Eastern Africa, Sennaar, Caffraria, Kordofan, and Latakoo.
THE LONG-TAILED, OR FOUR-FINGERED PANGOLIN.[66]
This Ant-eater is from two to three feet in length, and the tail is twice as long as the body. It inhabits the Guinea Coast and the Gaboon, and probably Senegal. It is a dark brown animal, with the hair of the face and under sides black in tint. There are eleven series of scales, with the end rounded, and a central prominence.
Buffon described a pale brown or horn-coloured, very scaly, long-tailed Ant-eater as a Phatagin, but it is correctly called Manis tricuspis, from the scales having three projections on them. It lives in Western Africa, Fernando Po, Guinea, and Sierra Leone.
THE GREAT MANIS.[67]
This scaled Ant-eater is thirty inches long in the body, and its tail measures twenty-five inches in length. The great tail lessens to the end, and the scales are striated at the base, the whole colour being pale brown. It is an interesting animal from its likeness to one of the Asiatic species, the Manis pentadactyla (Linn.); but the difference in the length of tail is remarkable. It has been found in West Africa, Guinea, and in the Cape Coast Castle district.
THE ASIATIC SCALY ANT-EATERS.
There is one point of great interest about the genus Manis, and it is that it is not restricted to Africa, for some species are found over a wide extent of country in India. They live there in a region from the Himalayan Mountains to Ceylon, and eastward to Sumatra and Java, and in Southern China as far as Amoy, Hainan, and Formosa. They afford an instance of closely-allied animals now living in large districts which are separated by seas, deserts, mountains, and rivers, and other impassable barriers. The Javanese are said to have called the animal, from the fact of its rolling itself up, Pangolin, and the Bengalese termed it the Reptile of Stone. The first to be noticed is—
THE SHORT-TAILED, OR FIVE-FINGERED PANGOLIN.[68]
This is supposed to be the Phattage of Ælian, and much resembles Temminck’s Manis from South Africa. It has a small head, which is pointed and long at the muzzle; the body is rather stout, and the tail is short, broad at the root. The back scales are in longitudinal rows, eleven in number, and they are smaller than those of the African kind. It has the under part of the body, head, and feet naked, and more or less hairy, and some long, fair-coloured hairs spring from between the scales. The middle claw of the fore-foot exceeds the others in size. They feed on white Ants especially. They are found in Bengal, Madras, and Assam.
A Manis with a tail as long as the body, and with the scales of the hind feet acutely pointed, and the front and hind claws nearly equal in size, is found in Sumatra and in Java. Finally, the other Asiatic kind, Manis Dalmannii, is found in the Himalayas, China, and possibly in Java.
All the species of the genus Manis, whether from Africa or Asia, are absolutely toothless, and the Edentate peculiarity is perfect, for there are no back teeth. The tongue is worm-like, round, very long, and can be stuck out far from the mouth, and it supplies the want of the teeth, but from having this long organ and no back teeth, the palate and the skull are very long and conical. Being without masticating teeth, the lower jaw is very flat and simple, and there is no ascending ramus. The muscles of the lower jaw being of secondary importance, the arch (zygoma) of bone between the face and the ear is incomplete, and the outside ear is very small. But the organ of hearing is somewhat complicated, and there is a large space in the temporal bone which communicates with the internal ear, so that one tympanum is in communication with the other.
Much saliva is required to moisten the tongue, and the sub-maxillary glands are therefore very large, and reach down under the skin of the neck on to the chest. The stomach is usually, if not always, found to contain stones which the creature has swallowed. Of course it can hardly tell what may be on its tongue in the dark Ants’ nest, and earth and stones are likely to rest on it and be swallowed, but the constant presence of these hard things may have something to do with the absence of the teeth, and the necessity of having a crushing material somewhere or other. The walls of the stomach are thin near the entry of the gullet tube, but towards the pylorus, or the right side end, the muscles are well developed, and the mucous membrane is very dense.
These animals use their claws for the purpose of digging holes in the ground, or in the Ants’ nests, for the sake of food, and the position in walking is with the front claws bent under, so that the whole weight of the front of the body is felt on the back (or upper part) of the claws. The hind feet are placed flat, and the sole and under part of the claws sustain the hinder quarters. The joints of the five fingers of the fore feet are so arranged that they can bend downwards only, and indeed they are more or less permanently bent, being kept in that position by strong ligaments. This assists the digging powers of the claws, which are, moreover, forked at their points in some species, and the wrist is rendered very strong by having the joints between two of its bones abolished, and they are united by bone, as in the carnivorous animals. The bones thus united are the scaphoid and semi-lunar bones. Every structure in the creature’s fore limbs tends to the promotion of easy and powerful digging, and as the motion of scratching the ground is directly downwards and backwards, the power of moving the wrist half round, and presenting the palm more or less upwards, as in the Sloths and in man, does not exist. In order to prevent this pronation and supination, the part of the fore-arm bone, the radius, next to the elbow, is not rounded, but forms part of a hinge joint. Finally, it is necessary to observe, that the middle claw is the longest of the five on all the extremities, and that as the animal does not require to reach over its head, there is no collar bone.
FIVE-FINGERED PANGOLIN.
The long tail of the Pangolins, stumpy at the end in some kinds, has a considerable number of bones, usually twenty-six; and the first of them joins on to the last of the back bones of the pelvis. This last, or sacral vertebra, unites on each side with the haunch bones (ischium), and there is no notch in the bone for the passages of the great nerves of the back of the leg, but a hole.
The thigh bone is flattened from before backwards, and the bones of the leg are wide apart, and all this gives extra powers to the muscles which have to direct the scraping and digging by the hind feet. The feet are solid and strong, and have not any of the inside turning and club-foot appearance of the Sloths, and the heel bone projects backwards.
There is an interesting peculiarity about the chest of the Pangolins, for the breast bone is very long, and the cartilage at its end is large, and has two long projections resembling those of the Lizards. The neck consists of seven vertebræ, and the back of thirteen, and there are three or four in the sacrum.
THE AMERICAN ANT-EATERS.
The adjective “long” may be applied to nearly all the structures of these animals. The tail, body, neck, head, snout, and tongue, and the hair are all very long, and the only things which are short are the ears. The observer is immediately struck with the curiously-shaped head, so narrow, low, and ending in a flexible and very slender snout, especially if the round tongue happens to be projecting out of the mouth, for it is longer even than the head, and is like a gigantic worm. The snout appears bent, and is made to look all the longer, by the eye being placed not far from the small ear. Then the huge bushy tail, flattened from side to side, as long as the body, has a fringe of very long and strong hair. The body itself moves on four powerful limbs, well clawed, and looks bulky from the quantity of hair on it, but usually it is thin. The animal, when it stands still, is higher at the shoulders than behind, and it rests on the sides of the fore-feet, where there is a callous pad, the claws being bent inwards and under, and not touching the ground with their tips. The under part of the hind feet bears the weight of the hind limbs. It is about four feet and a half in length from the snout to the tail, the tail being rather more than three feet in length, and the height is about three feet and a half. So long is the head, that it measures thirteen inches and a half from the ear to the snout, and the tongue can be projected for sixteen or eighteen inches, and is, when brought back into the mouth, bent so that its tip looks backwards towards the throat.
The animal belongs to a group of the Edentata (for it is toothless) which has the following genera:—One genus, which is now being considered, is Myrmecophaga—μύρμης (an Ant), and φαγεῖν (to eat)—a second is Tamandua, and the third is Cyclothurus, from κυκλωτός (rounded). The animals of this group represent in South America the Pangolins and Cape Ant-eaters of the Old World.
The species of the genus Myrmecophaga, which has been thus slightly alluded to, is called the Maned Ant-eater.
THE GREAT ANT-BEAR.[69]
The habits of this animal, which has been named Great Ant-Bear by the English and Spaniards, have been described as follows:—“The habits of the Great Ant-Bear are slothful and solitary; the greater part of his life is consumed in sleeping, notwithstanding which he is never fat, and rarely even in good condition. When about to sleep he lies on one side, conceals his long snout in the fur of the breast, locks the hind and fore claws into one another, so as to cover the head and belly, and turns his long, bushy tail over the whole body in such a manner as to protect it from the too powerful rays of the sun. The female bears but a single young one at a birth, which attaches itself to her back, and is carried about with her wherever she goes, rarely quitting her, even for a year after it has acquired sufficient strength to walk and provide for itself. This unprolific constitution, and the tardy growth of the young, account for the comparative rarity of these animals, which are said to be seldom seen, even in their native regions. The female has only two mammæ, situated on the breast, like those of Monkeys, Apes, and Bats. In his natural state the Ant-Bear lives exclusively upon Ants, to procure which he opens their hills with his powerful crooked claws, and at the moment that the insects, according to their nature, flock from all quarters to defend their dwellings, draws over them his long, flexible tongue covered with glutinous saliva, to which they consequently adhere; and so quickly does he repeat this operation, that we are assured he will thus exsert his tongue and draw it in again covered with insects twice in a second. He never actually introduces it into the holes or breaches which he makes in the hills themselves, but only draws it lightly over the swarms of insects which will issue forth, alarmed by his attack. ‘It seems almost incredible,’ says D’Azara, ‘that so robust and powerful an animal can procure sufficient sustenance from Ants alone; but this circumstance has nothing strange in it to those who are acquainted with the tropical parts of America, and who have seen the enormous multitudes of these insects, which swarm in all parts of the country to that degree that their hills often almost touch one another for miles together.’ The same author informs us that domestic Ant-Bears were occasionally kept by different persons in Paraguay, and that they had even been sent alive to Spain, being fed upon bread-and-milk mixed with morsels of flesh minced very small. Like all animals which live upon insects, they are capable of sustaining a total deprivation of nourishment for an almost incredible time.”
GREAT ANT-BEAR.
The Great Ant-Bear is found in all the warm and tropical parts of South America, from Colombia to Paraguay, and from the shores of the Atlantic to the foot of the Andes. His favourite resorts are the low, swampy savannahs, along the banks of rivers and stagnant ponds. He is found also frequenting the humid forests, but never climbing trees, as falsely reported by Buffon, on the authority of La Borde. His pace is slow, heavy, and hesitating; his head is carried low, as if he smelled the ground at every step, whilst his long, shaggy tail, drooping behind him, sweeps the ground on each side, and readily indicates his path to the hunter; though, when hard pressed, he increases his pace to a slow gallop, yet his greatest velocity never half equals the ordinary running of a man. So great is his stupidity, that those who encounter him in the woods or plains may drive him before them by merely pushing him with a stick, so long, at least, as he is not compelled to proceed beyond a moderate gallop; but if pressed too hard, or urged to extremity, he turns obstinate, sits up on his hind quarters like a Bear, and defends himself with his powerful claws. Like that animal, his usual, and indeed only, mode of assault is by seizing his adversary with his fore paws, wrapping his arms round him, and endeavouring by this means to squeeze him to death. His great strength and powerful muscles would easily enable him to accomplish his purpose in this respect, even against the largest animals of his native forests, were it but guided by ordinary intelligence, or accompanied with a common degree of activity. But in these qualities there are few animals, indeed, which do not greatly surpass the Ant-Bear, so that the different stories handed down by writers on natural history from one to another, and copied, without question, into the histories and descriptions of this animal, may be regarded as pure fiction. For this statement we have the express authority of Don Felix d’Azara, an excellent observer and credible writer, from whose “Natural History of the Quadrupeds of Paraguay” we have derived the greater portion of the preceding account of the habits and economy of this extraordinary animal. “It is supposed,” says Don Felix, “that the Jaguar himself dares not attack the Ant-Bear, and that if, pressed by hunger, or under some other excitement, he does so, the Ant-Bear hugs him and embraces him so tightly, as very soon to deprive him of life, not even relaxing his hold for hours after life has been extinguished by his assailant. It is very certain that such is the manner in which the Ant-eater defends himself; but it is not to be believed that his utmost efforts could prevail against the Jaguar, which, by a single bite or blow of his paw, could kill the Ant-eater before he was prepared for resistance; for even in so extreme a case, his motions are so slow and so heavy, that he takes some time to get himself ready, and besides being unable to leap, or to turn with even ordinary rapidity, he is necessarily forced to act solely on the defensive.” The flesh of the Ant-eater is esteemed a delicacy by the Indians and negro slaves, and, though black, and of a strong musky flavour, is sometimes even met with at the tables of Europeans.
This large Ant-eater, grey in colour, with a black-coloured throat and a triangular spot, black in tint, ascending obliquely over each shoulder, has four claws on the fore limb and five on the hinder extremity. The claws are grooved underneath, and are not split or forked as in the Manis, and they, and especially the great middle claw, are protected by an expansion of bone from the last joint of the digits, or toes. This envelopes the base of the claw, except quite underneath, leaving the tip free to perform its office without endangering the tender base. The tips are protected, moreover, in the fore limbs by the position assumed during standing and walking, for they are then turned in and do not touch the ground; but this is not the case in the feet, for the Great Ant-Bears rest on their soles. Without teeth, and having an incomplete arch of bone between the cheek and ear bones, they possess a long palate, so long, indeed, that when the long nose cavity opens into the throat in the skeleton certain bones called pterygoid, or wing-shaped, form part of its boundary. This is unusual amongst the Mammalia, and Huxley observes that it is only found in some of the Whale tribe (Cetacea). Moreover, it is not noticed in any other vertebrate animals except the Crocodiles. The skull is very low and long, and the framework of the tongue is as important as that of the jaws. This kind of Ant-eater has imperfect collar bones. As in the other Ant-eaters there is in this one a very muscular condition of the right side of the stomach.[70]
THE TAMANDUA.[71]
The Tamandua is much smaller than the Great Ant-eater, and is, were it not for its long snout and tail, somewhat like a Sloth. It is nearly as large as one of these animals, and has a long head, small rounded ears, and small mouth. The body, some two feet in length, is rather short, and is covered with short, silky, or woolly shining hair, of almost uniform length. The fore limbs are very stout, especially above the elbow, and the hind ones rest on the rather long sole. The tail is about a foot and a half in length; it is stout at its root, and round and tapering to the blunt end, is minutely scaled, and covered in some places with short hairs. The fore claws are bent on the hand, and the animal walks on their outer and upper surface, using them also to clasp and to hang on in climbing. The tail is more or less prehensile. The colour of the hair and the markings varies much in the species, and in captivity the rusty straw-colour of the body becomes whiter; but there is a line of black on the upper part of the chest reaching over the shoulders and between them and the neck on to the back, and also several black patches over the tail and on the flanks.
The Tamandua is an inhabitant of the thick primeval forests of tropical America, and lives in Brazil and Paraguay. It is rarely found on the ground, but resides almost exclusively on trees, where it lives upon termites, honey, and even, according to the report of D’Azara, bees, which in those countries form their hives among the loftiest branches of the forest, and, having no sting, are more readily despoiled of their honey than their congeners of Great Britain. When about to sleep, it hides its muzzle in the fur of its breast, falls on its belly, letting its fore feet hang down on each side, and wrapping the whole tightly round with its tail. The female, as in the case of the Great Ant-eater, has but two pectoral mammæ, and produces but a single cub at a birth, which she carries about with her on her shoulders for the first three or four months. The young are at first exceedingly deformed and ugly, and of an uniform straw-colour.
The animal is called Cagouaré by the Guaranis, on account of the noxious and infected vapours of the forests in which alone it is found, the word literally signifying, in the language of those Indians, “the inhabitants of a stinking wood or marsh.” Such at least is D’Azara’s interpretation of the term, though it appears more probable that it may refer to the strong disagreeable odour of the animal itself, which, this very author informs us, is so powerful that it may be perceived at a very great distance, particularly when the animal is irritated. Tamandua is the name by which it is known to the Portuguese of Brazil; the French and the English call it Fourmilier and Little Ant-Bear.
THE TWO-TOED ANT-EATER.[72]
These little animals appear, at first sight, to resemble Sloths with tails; and their round heads, furry bodies, and two claws on the fore limb, add to the resemblance. They are essentially arboreal animals also, but they have long and useful tails, and live on insects. They hunt their insect prey in the forests of Costa Rica, Honduras, and Brazil. Their two-clawed hands are remarkable, for the rudiments of the thumb and little finger are hidden beneath the skin, and the claws are placed on the first and second digits. The third digit has no claw. There are four claws on the feet, so that in this arrangement the animal is peculiar amongst the Ant-eaters. It is not larger than a common Squirrel, and the general shape of the body is like that of a Tamandua on a small scale. Its whole length, from the snout to the origin of the tail, is but six inches, and of the tail, seven inches and a quarter. This is consequently rather longer than the body; it is thick at the root, and covered with short fur, but tapers suddenly towards the point, where it is naked and strongly prehensile. The muzzle is not so long, in proportion, as in the other two species; the tongue also is shorter, and has a flatter form; the mouth opens further back in the jaws, and has a much larger gape, the eye being situated close to its posterior angle; the ears are short, rather drooping, and concealed among the long fur which covers the head and cheeks; the legs are short and stout; and the hair, very soft and fine to the touch, is three-quarters of an inch in length on the body, but much shorter on the head, legs, and tail. The general colour is that of straw, more or less tinged with maroon on the shoulders, and particularly along the median line of the back, which usually exhibits a deep line of this shade. The feet and tail are grey.
This species is said to have four mammæ, two pectoral, as in those already described, and two others on the abdomen. It is reported, nevertheless, to have but a single cub at birth, which it conceals in the hollow of some decayed tree. The habits and manners of this little animal, hitherto very imperfectly known to naturalists, are well described by Von Sach, in his “Narrative of a Voyage to Surinam.”
“I have had two little Ant-eaters, or Fourmiliers, which were not larger than a Squirrel. One was of a bright-yellow colour, with a brown stripe on the back, the other was a silvery-grey, and darker on the back. The hair of each was very soft and silky, a little crisped; the head was small and round, the nose long, gradually bending downwards to a point; it had no teeth, but a very long round tongue; the eyes were very small, round, and black; the legs rather short; the fore-feet had only two claws on each, the exterior being much larger and stronger than the interior, which exactly filled the curve or hollow of the large one; the hind feet had four claws of a moderate size; the tail was prehensile, longer than the body, thick at the base and tapering to the end, which, for some inches on the under side, was bare. This little animal is called in Surinam ‘Kissing-hand,’ as the inhabitants pretend that it will never eat, at least when caught, but that it only licks its paws, in the same manner as the Bear; that all trials to make it eat have proved in vain, and that it soon dies in confinement. When I got the first, I sent to the forest for a nest of Ants, and during the interim I put into its cage some eggs, honey, milk, and meat; but it refused to touch any of them. At length the Ants’ nest arrived, but the animal did not pay the slightest attention to it either. By the shape of its fore-paws, which resemble nippers, and differ very much from those of all the other different species of Ant-eaters, I thought that this little creature might perhaps live on the nymphæ of Wasps, &c. I therefore brought it a Wasps’ nest, and then it pulled out, with its nippers, the nymphæ from the nest, and began to eat them with the greatest eagerness, sitting in the posture of a Squirrel. I showed this phenomenon to many of the inhabitants, who all assured me that it was the first time they had ever known that species of animal take any nourishment. The Ants which I tried it with were the large white termites upon which fowls are fed here. As the natural history of this pretty little animal is not much known, I thought of trying if they would breed in a cage; but when I returned from my excursion into the country I found them both dead, perhaps occasioned by the trouble given to procure the Wasps’ nest for them, though they are here very plentiful; wherefore I can give no further description of them, than that they slept all the day long, curled together, and fastened by their prehensile tails to one of the perches of the cage. When touched they erected themselves on their hind legs, and struck with the fore-paws at the object which disturbed them, like the hammer of a clock striking the bell, with both paws at the same time, and with a great deal of strength. They never attempted to run away, but were always ready for defence when attacked. As soon as evening came, they awoke, and with the greatest activity walked on the wire of the cage, though they never jumped, nor did I ever hear their voice.”
TWO-TOED ANT-EATER.
All these Ant-eaters have great glands (sub-maxillary) for the purpose of secreting the sticky saliva, and the tongue is most movable, and wriggles like an eel in feeding on milk. The Little Ant-eater has a rete mirabile of blood-vessels.
Another Cyclothurus lives in Costa Rica, which is golden-yellow in colour, and silky in its hair. It has a broad black stripe on the back.
CHAPTER III.
THE ARMADILLO FAMILY.
The Armour-plates—How the Shields are formed—Their connection with the Body—Description of the Animals—Mode of Walking—Diet—Skeleton—Adaptation of their Limbs for Burrowing—Classification—[THE GREAT ARMADILLO]—Appearance—Great Burrower—[THE TATOUAY]—[THE POYOU, OR YELLOW-FOOTED ARMADILLO]—[THE PELUDO, OR HAIRY ARMADILLO]—[THE PICHIY]—[THE PEBA, OR BLACK TATOU]—[THE MULE ARMADILLO]—[THE BALL ARMADILLO]—Dr. Murie’s Account of its Habits—Description—The Muscles by which it Rolls itself up and Unrolls itself—[THE PICHICIAGO]—Concluding Remarks: Classification of the Order, Fossil Edentates, the Allied Species of Manis in South Africa and Hindostan.
BONES OF CLAW OF GREAT ARMADILLO.
THESE South American animals are more or less covered with a hard bony crust, separated into shields and bands, which are more or less movable, owing to the presence of special skin-muscles. In the most perfectly armoured there are four distinct shields and a set of bands, a certain amount of motion being possible between their edges. Of the shields, one covers the head, another the back of the neck, a third protects the shoulders like a great cape, and the fourth arches over the rump like a half dome, and is, in some, attached by its deep structure to the bones of the hip and haunch. The movable bands cover the back and loins, and are between the third and fourth shields. The tail may further be invested by incomplete bony rings, and scattered scales, and others are distributed over the limbs. This covering is, according to Professor Huxley, strictly comparable to part of the armour of the Crocodile; and the Armadillos are the only Mammals possessing such structure. The shields and bands are formed of many scales, or scutes, which are ossifications of the skin, and they may be of many kinds of shape—four, or many-sided—being united by sutures, and they are incapable of separate motion. The shields and bands, however, vary much in their number, size, and perfectness in the different animals, which, being armoured, the Spaniards called Armadillos; and, indeed, the number of bands in the back and loin division varies in individuals of the same species. These bands cover the flanks, and, with the shields fore and aft, protect the limbs, which are often more or less hidden by a growth of hair. The bands, moreover, by being movable one on the other, enable the rest of the armour to accommodate itself to the motions of the body, so that some roll themselves up, as in a ball shape. There may be few or many bands present, and the extreme numbers are three and thirteen. The Armadillos are of different sizes, and whilst the smallest may be only ten inches in length without the tail, the largest are more than three feet long. The head is long, and broad at the neck, the ears are usually long, the neck is short, the body is long, round, and low, and the length of tail varies much in different kinds. Where the head shield joins that of the shoulders, there is a space for the movement of the short neck; but this is protected by a backward projection from the head shield. The throat, under parts, and thighs are not protected by armour, except here and there by small plates in the skin, or by a granulated state of it; and they are naked or hairy. Even between the bands on the back there are often long hairs, and the tail fits into a kind of notch in the last shield of the body, and its plates are close in almost all Armadillos, but not united. So that much more motion is given to it and to the body than might be expected by the muscles during their action beneath the more or less soldered bony skin. The flat top to the head, and the long muzzle, are useful to the Armadillos in their burrowing, and this is assisted by short and strong limbs armed with powerful claws. Some of the Armadillos are even capable of running with some speed; and the little Six-banded Armadillo, or Poyou, and the Matico, are very restless and active in captivity. With one exception, these animals move with the flat of their feet and hands on the ground; all have five hind claws, but there is some variation in the number of the fore claws, which may be four or five. They have simple cylindrical molar teeth, which, according to the species, are from seven or eight to twenty-five on each side of each jaw, and they are separate, standing apart from one another. Moreover, they are so arranged that when the mouth is closed, the upper teeth fit into the spaces between the under ones, and the under teeth into those of the upper, so that their grinding surfaces wear down into ridges. In one kind, there are some teeth in the pre-maxillary bones; but all the others have only molar teeth, which do not, however, go very far back, for there are none on the ascending ramus of the lower jaw. They are not, therefore, animals which prey upon their fellows, but are vegetable, insect, and probably carrion eaters. They dig and burrow, and their sense of smell is acute. This is assisted by the position of the nostrils in the long muzzle, for they are not at its tip, but rather underneath, so that they open downwards. In fact, the ends of the bones of the nose project in front of the pre-maxillary bones. The armour is doubtless useful against the attacks of their many carnivorous and reptile enemies; it assists them in burrowing, keeps off pressure, and may protect those which live in forests against a falling bough. They are passive creatures, mostly nocturnal in their habits, and their skeleton is strengthened in some parts in relation to its armour and its office.
SKELETON OF THE ARMADILLO.
Thus the spine of the second vertebra is tall and compressed, and reaches backwards over those of the third and fourth vertebræ, and it coalesces with them. The bodies of these vertebræ also join more or less solidly, and there are no (or very minute) spines on the last three cervical vertebræ. This gives a strange appearance to the skeleton, which is increased by the length of the spine of the first vertebra of the back (dorsal). In order to support the back shield, the projections from the back bones are greatly developed, and two side processes stand out on either side of the spinous one. Moreover, there is much fixity between the last dorsal and lumbar vertebræ, and the strong and long sacrum beneath the last shield is formed by the junction of the back bones of the root of the tail with the true sacral vertebræ. Finally, the transverse processes of some of the upper tail vertebræ are united to the pelvic bones. There is a corresponding strengthening of the chest, and a broad flat first rib accompanies an expanded condition of the upper part of the breast bone; and this bone is jointed with bony sternal ribs, which unite on the side of the chest with the ordinary ribs of the spine.
SKULL OF THE ARMADILLO.
As they are rapid burrowers, the limbs are fashioned with a view of favouring this kind of life, the general skeletal peculiarities of the Edentata being more or less preserved at the same time. They have a collar bone, and the blade bone is long, rather narrow, and has a tall, long spine, and a kind of offshoot from the back edge. The humerus of the arm is short and robust, strongly marked by ridges and depressions for the great muscles of the shoulder and chest, and the fore-arm is characterised by the disproportionate size of its two bones. The ulna has a very long and stout elbow process (olecranon) for the attachment of the muscles, which can force the hand strongly on to and into the earth, and drag it out, and its length makes the whole bone twice as long as the radius. The thigh bone has a strong crest, arising from the great trochanter, and extending downwards nearly the whole length of the bone; moreover, the great trochanter has a large process on the middle of its outer edge. The bones of the leg are broad, arched, and united at both ends, and the heel bone reaches far back, in order to give strength to the squatting position taken up when the animal is burrowing. The eye is placed rather high in the head, is protected above by the outer edge of the head armour, and by some small surrounding scales. It looks as a rule outwards. The lower jaw is long, and has a back angle, sometimes of some size; the cheek bone unites to the temporal bone, and the arch is complete. In the face the intermaxillary bone is well developed, and there is often a crest of bone passing over the top of the skull from side to side over the occiput, which is in relation to the head armour. The brain is small; the back or little brain is not covered by the brain proper, whose convolutions and processes are few and simple. The olfactory lobes project.
GREAT ARMADILLO.
These armoured, round-bodied, short-legged, great-clawed animals are numerous, and there are several species, which need not, however, be collected into more than two genera. But it is by no means easy to arrange those of the first genus—the True Armadillos, genus Dasypus—in any other than an arbitrary and very artificial classification. Usually they are grouped and separated by the relative number of digits or claws on the fore and hinder extremities; by the presence or absence of teeth in the intermaxillary bones; by their ability to roll up; and by the excessive or the small number of their teeth. The method of walking, whether on the sole or on the tips of the claws, and the number of the bands, have been partly employed in classification, but their number is often variable in individuals of the same species.
BRAIN OF THE ARMADILLO.
The Priodontes have but one species, which is readily distinguished by its superior size, besides by its great number of teeth, of which there are from twenty-two to twenty-four small ones on each jaw on each side, making from eighty-eight to ninety-six in all.
THE GREAT ARMADILLO.[73]
This is an inhabitant of Brazil, and of the northern parts of Paraguay and of Surinam, and is a dweller in the forest, being never found far out on the plains. The head is seven inches and a half long, and the ears, usually pointed and laid backwards, are not quite two inches in length. The head and body, without the tail, measure three feet and some inches, whilst the thickly-rooted but rapidlytapering tail is about a foot and a half in length. Hence the head is small for the body in this Armadillo, and the forehead is protuberant, and the face is very tubular and cylindrical-looking. The shoulder and croup shields are not expanded and solid, but consist of nine and eighteen rows of plates respectively, and the intermediate part of the body has twelve or thirteen movable bands, each of which is made up of rectangular scales, or scutes, about half an inch square. The circumference of the root of the tail is upwards of ten inches, and the organ is covered with plates, disposed in rings at the root, and not farther down, but forming spiral or crescent-shaped lines throughout the rest of its length.
The Great Armadillo is a persevering and most rapid burrower, and the fore limb and hand are singularly modified for the purpose of enabling rapid digging and removal of the soil. The olecranon process of the ulna is enormous, and the muscle of the deep flexor or tendon of the claws is ossified and turned into a hand bone. The metacarpal bones of the thumb and first finger are small, and so are the slender digits, but that of the middle finger is irregularly rectangular, and is broader than long, and the digit which it supports is extraordinarily short, stout, strong, and broad. Its corresponding bones of the fourth finger are similarly formed, but are somewhat smaller, and the fifth finger is very small. The nail phalanx of the middle finger is large and strong, being curved outwards, and having a large horny hood, or core, at its base, for the lodgment of the claw. There are five claws on the hands and feet, and the Armadillo moves on the flat of its feet, being plantigrade. There is no doubt that, aided by these digging weapons, and being of considerable stoutness, the animal makes long and deep burrows. It feeds on roots, fallen fruit, and insects, and there is a story that it seeks carrion, and it used to be said that the collectors of Cinchona bark in the dense forests, when they lost a companion by death, were obliged to bury the body in a grave surrounded with a double row of stout planks, to prevent its being scratched up and devoured by the Great Armadillo. Planks must be scarce, however, in those localities, and difficult to carry; and probably there are other inhabitants of the woods besides the Armadillos which would discover and drag out a corpse. To assist the scratching and digging, the soles of the feet are partly covered with flat scales.
The Kabassous have the fore and hind extremities furnished with an equal number of (five) fingers and toes respectively, but the number of teeth is, altogether, from thirty to forty.
THE TATOUAY.[74]
This Kabassou has the five fingers disposed obliquely; and the great middle and fourth claws resemble those of the gigantic Armadillo. It is named in allusion to its tail, which is more or less naked, and nearly uncovered with rings or plates, so that it has not the usual tube-like protection, or beautifully ornamented crust seen in some Armadillos. The tail is about seven inches and a half long, and is round and pointed, having only a few hard crusts beneath, near the outer third, where it often trails on the ground. The rest of its root is covered with soft brown fur, interspersed with a few stiff short hairs on the upper surface. The ears are large, being nearly two inches in length, and they form a segment of a circle in figure. The body is round, and the shields of the shoulder and croup have seven and ten rows of scales respectively, each scale forming an oblong rectangle, those near the root of the tail being the largest. The movable bands are thirteen in number, and are composed of much smaller scales than those of the shields, and they have a nearly square outline. The head is long and larger in proportion than that of the Great Armadillo, and it has not the very cylindrical appearance noticed in that and some other species. The arrangement of the claws resembles that of the Great Armadillo, whose they almost equal in size. The female has two pectoral mammæ.
It inhabits Guiana, Brazil, Peru, Paraguay, and Surinam, and but little is known of the habits of these Armadillos. They burrow easily and rapidly, and their great claws enable them to grasp the earth, and fix themselves so thoroughly that a great amount of exertion is required to pull them out of a burrow. They live on insects and on vegetable matters.
The Encouberts of Cuvier have five toes on the fore and hinder extremities, and nine or ten teeth on each side of the jaws, and there are two teeth in the intermaxillary bones of the upper jaw, representing the incisor teeth of ordinary Mammals, and thus forming an exception, not only to the other Armadillos, but even to the order of Edentata, as represented in the recent period.
THE POYOU, OR YELLOW-FOOTED ARMADILLO.[75]
This little Armadillo, which in captivity and in the natural state is remarkable for its boldness and restlessness, is a native of Brazil and especially of Paraguay, where it is common. It has a large, flat, nearly triangular top to its head, the face is short, the muzzle obtuse, and the ears erect and of moderate size. It has sharp little eyes. It measures about sixteen inches from the nose to the tail, and this is about seven or eight inches long. The number of movable bands is often six, but this is not the invariable number, for there may be seven or eight. The tail is surrounded, at its base, with three or four bony rings, and throughout the rest of its length is nearly covered with regular tuberculous scales, the separations between the bands showing some long bristly grey hairs. The body is flat and broad, and has short legs, and the creature runs with a very active and determined gait. It is a strong little thing, and it is said that when it is chased, it will often get away from a man by sheer speed and activity. When any noise is made at the entrance of its burrow, or if it is teased by spectators around its cage, it comes forth and grunts like a Pig, and looks at the disturber with a bold inquiring look. When it is attacked it is powerless, and seems incapable of making any defence, but it retreats to its burrow, and getting to the bottom of it, digs deeper still. Its power of burrowing does not seem to be much diminished by the limited rotation of the fore-arm, to which there is no pronator quadratus, but a well-developed pronator teres.
POYOU.
The Poyou feeds much on carrion, and for this reason its flesh, though fat, is never eaten by the inhabitants of European origin, though the Indians make no distinction in this respect between it and other Armadillos. When it stops or rests, it has a custom of squatting close to the ground like a Hare on her form, and in this position the great breadth of the body becomes apparent.
The hinder shield has two hairs on the hinder side of each of its dorsal scales, and the under part of the body has scattered bristles on it. The female has two pectoral mammæ.
The next two Armadillos to be noticed were formerly included in the same group as the Poyou, but as they have not the incisor teeth on the intermaxillary bones, they are placed in the sub-division Euphractes.
THE PELUDO, OR HAIRY ARMADILLO.[76]
The long, silky, half bristly, abundant black hairs of this little Armadillo are the principal characteristics, which separate it, so far as its external construction is concerned, from the Poyou just noticed. It is smaller, however, the head measuring nearly four inches in length, and the whole body about two inches less than Dasypus sexcintus. The ears are long, large, and elliptical, and are pointed outwards, and the muzzle is broad. The forehead is broad and covered with rugged scales. The bands are six or seven in number, and the border of the shield, as well as that of the movable bands below, is indented in a remarkable manner, and forms sharp, regular points. There are eight teeth on each side, above and below, and the body, hairy as it is, is much scaled interiorly and on the limbs. The tail is long and slender, and only hairy at the root. This species does not inhabit Paraguay, nor probably is it found in the Brazils, but it exists in multitudes in the Pampas north of the Rio Plata, and Mr. Darwin noticed it in Chili. Its habits, according to that most accurate observer, are nocturnal, but D’Azara, to whom natural history owes very careful descriptions, states that “in an expedition which I made into the interior, between the parallels of 35° and 36° south latitude, I met with vast multitudes of this species of Armadillo, so that there was scarcely an individual of the party who did not daily capture one or two at least; for, unlike the Poyou, which moves abroad only at night, this animal is to be found at all times, and if alarmed, promptly conceals himself, if not intercepted. In March and April, when I saw them, they were so extremely fat that their flesh surfeited and palled the appetite; notwithstanding which, the pioneers and soldiers ate them roasted, and preferred them to beef and veal. This Hairy Armadillo, like others of the genus, has undoubtedly a very acute sense of smell, since it scents the carcases of dead Horses from a great distance, and runs to devour them; but as it is unable to penetrate the hide, it burrows under the body until it finds a place which the moisture of the soil has already begun to render soft and putrid. Here it makes an entrance with its claws, and eats its way into the interior, where it continues feasting on the putrid flesh, till nothing remains but the hide and bones, and so perfectly do these preserve their position, that it is impossible, from a mere external view, to anticipate the operations which the Armadillos have been carrying on within.” The same author states that this species never constructs burrows to reside in, that it avoids low, damp situations, and is found only on the dry upland plains. Probably there is more than one Hairy Armadillo.
THE PICHIY.[77]
This little Armadillo is only fourteen inches long, tail included; its scaling is very handsome, and there are six or seven bands according to the individual and age. The head is covered with close scales, which are elliptical behind, and concealed under the others in front, and the whole top has a triangular outline, hiding the eye much. The scales on the front shield are large, and are hexagonal or pentagonal, and the croup shield has the angular endings noticed in the last species. The scales of the bands and of the shields generally are beautifully ornamented with lines, depressions, and little tubercles, which are more or less concentric. There is some hair on the long neck, and on the legs and tail. The five digits and claws on the fore limbs are moderately developed, for the thumb is very small, and the fourth finger only a little longer. But the index is long, with a short claw, and the second has a stouter and longer claw, and the third is shorter. It has a slender snout and small ears.
Mr. Darwin writes that it “prefers a very dry soil and the sandy dunes of the coast of Chili, where for many months it can never taste water. In soft soil, the animal burrows so quickly that its hind quarters would almost disappear before one could alight from one’s horse.” It also inhabits the Pampas to the south of Buenos Ayres, and extends from 36° lat. southward to the confines of Patagonia. It inhabits burrows, to which, however, it does not confine itself during the day. Its flesh is said to be remarkably tender and well tasting. It is a hardy species, and can live in the dreary solitudes of Port Desire on the east coast.
The Cachicames, another group of Armadillos, were so called after the Indian name for a black kind, which has a very long tail, and which is the type of it.
The two kinds included in the group have four fingers, and five toes, which are separate, and the backs of the feet are round and covered with scales. The claws are conical, and the animal walks, as it were, on the toes more than on the sole, being thus digitigrade. The teeth number about eight on each side above and below.
THE PEBA, OR BLACK TATOU.[78]
This Armadillo has a very wide geographical range, extending from Texas, through Central America to Guiana, Brazil, and Paraguay, and a variety called Dasypus Kappleri inhabits Surinam. It has great ears, which are long and placed very close together, and the muzzle at the end of the long, tapering face is not unlike that of the snout of a Hog in shape. The head is small, long, and straight, but the mouth is large. There are eight teeth on both sides of both jaws. The body is hairy below the shields and bands, which are largely developed. Then the neck and shoulder shield extends far back and comes as low as the elbow, and is composed of numerous scales disposed in many concentric rings, having the concavity in front, the first embracing the neck in its curve. The croup shield extends from the back to the origin of the tail, and reaches as low as the knees, and the concavity of its rings is turned towards the rear, the last embracing the tail. These scales are hexagons. Between the shields the bands are marked with zigzag lines forming very acute angles, and in some degree gliding over one another according to the movements of the animal. Out of fourteen specimens, two had six, one had seven, seven had eight, and there were four with nine bands; the full-grown ones have the greatest number. The head shield descends from the ears to the muzzle, and covers the cheeks as far down as the eyes, and there are small, interspersed, detached scales over the throat, the under jaw, the legs, and feet. The body is sixteen inches long, and the tail is nearly as long—fourteen inches—and is stout at the root. One variety of the species has some of the rings of the tail soldered into a case, which is used as a horn by the Indians. It is a timid, nocturnal animal, tolerably swift-footed and very expert in burrowing. It is never found in the woods, but delights in the open plains and cultivated fields, and is much hunted on account of the delicacy of the flesh, which, when roasted in the shell, is fat, and something better than Sucking-pig in taste. These long-tailed Armadillos bury garbage and flesh in their burrows, and eat it at their leisure.
Another species of this group is the Mule Armadillo (Dasypus hybridus, Desmarest), which has long, straight ears and a short tail. It roams farther north than the other kind, and is common on the Pampas, and is not nocturnal, nor does it burrow very easily. The female has from eight to twelve young at a birth, and the individuals of a litter are often of one sex.
The Armadillos of all kinds, it is said, only have one litter a year, and then the young are numerous, but the mother has never more than four teats, and many have only two.
The last group of the Armadillos, the Tolypeutes, contains some remarkable species, which have the power of rolling themselves up as in a ball-shape, and they walk in a most extraordinary manner on the tip of long and powerful front claws, and also on the flat and tip of the hind ones.
THE BALL ARMADILLO.[79]
This is a small and very beautifully ornamented Armadillo, which has three free central bands and a short tail, with large fore and aft shields. It rolls itself up on the slightest alarm, so that the great shoulder and croup shields meet, the head and tail fitting in exactly, in front, so as to close up the body very safely. The little animal, which is rarely more than fifteen inches long, and has a tail of a couple of inches in length, is found in Brazil, Paraguay, and Buenos Ayres, and its walking on the long, stout claws of the fore legs gives it a very curious and unsteady appearance.
It is an active, sprightly, light-footed little thing, according to Dr. Murie, and is constantly on the move, going here and there with much vivacity. Poising itself on tiptoe, it trots backwards and forwards as if on some urgent errand. In captivity the food was raw meat, boiled eggs, and bread-and-milk. In the forest land, where it dwells along with its fellow armoured creatures, it has the advantage of being able to curl itself up, and to present no tangible part of its body to the host of mischievous Monkeys of its locality. The other Armadillos, when retiring to their holes, are often set upon by their lively quadrumanous neighbours, and are dragged out by the tail with great gusto; but the little Tolypeutes curls himself up and laughs at the disappointed Monkeys, who can find nothing to pull at about him.
BALL ARMADILLO.
The shoulder shield comes down like a flap, far in front, and the croup extends behind in the same way, and they and the bands have large scales, which are very pretty in shape and ornament. The shields are very stout, and so is the skeleton within. The fore foot has three large clawed toes, on the tips of which the animal walks. The thumb of the fore extremity is to be seen in the skeleton, but is not always visible in the skin, and it is very small and high up; the index is long, and the claw also, and it is slightly bent, but sharp at the tip. The next claw is the largest and longest, and has a cutting edge at the back and outer part, and the point is sharp. The next digit is smaller. In the hind foot there are five toes, one being high up and rudimentary, and the second and third having broad, flat, curved, short nails, the third being the greatest. The fourth nail is smaller, and they are all placed more or less flatly on the ground.
The shell of this Armadillo is blackish-brown, and the skin between the central bands is bald and smooth. There are nine back teeth on each side in both jaws, and there are none in front. The muscles which enable this Armadillo to bring its tail and nose together and to form a ball shape, are not simply expansions of the common muscular tissue, which exists deeply in the skin in so many animals, but are special structures. The most important are in relation to the position of the head, neck, limbs, tail, and the shields and bands, when the body is about to be and while it is being rolled up; and these roller-up muscles are so arranged as to permit of the large liver and other internal organs not suffering pressure during their natural or temporary displacement. On the other hand, the unrollers act when the body and bones are in the rolled-up condition. The muscles of the back are very tendinous, and to a degree they unroll the animal, but this is also performed by muscles which are attached underneath the first movable band of armour, and to the front part of the spine of the blade bone; this will tend, when it contracts, to pull out the legs and protrude the fore part of the body, the centre being still rigid. Another drawer-back of the bladebone assists in this action, and it is inserted into the front or chest shield. The rolling up is done by the action of muscles which draw the nose down, so as to make the long head at right angles to the neck; then the fore-legs and bladebones are drawn in and up. At the same time, the muscles which pull down the tail act on the hind shield, and draw it down and forwards. The legs are pulled up, and then a great muscle, which is largely attached to the front and hind shields, and has a tendon-like expansion in the middle of its course beneath the movable bands, contracts and pulls front and stern together. The muscles of the loins, which in jumping animals bring the spine to a curve, do not act, and indeed are excessively small. The chief bend in the back is between the second and third lumbar vertebræ. (Murie.)
GENUS CHLAMYDOPHORUS.—THE PICHICIAGO.[80]
PICHICIAGO.
This is an Edentate animal, resembling the Armadillos more than any others, and is about six inches in length. It has a conical-shaped head, a large full chest, short clumsy powerful fore limbs, with four great nails rising gradually one above the other, the external shortest, and broadest; and the whole so arranged as to form a sharp-cutting instrument, rather scooped, and very convenient for progression under ground. The back and croup are broad and high, and the tail is small. The hind legs are weak and short, the feet being long and narrow, and there is a well-defined heel. The foot is arched, the toes are separate, and the nails are strong. The whole surface of the body is covered with fine silk-like hair, which covers over the limbs on to the palms. But the most striking peculiarity is the long-banded shell, which is loose as it were throughout, being attached to the back immediately above the spine by cellular tissue. It rests on two knobs on the frontal bones, and these are the great attachments of this important covering. There are twenty-four bands and no separate shields, and their consistence is somewhat more dense than leather of the same thickness. They are composed of scales or plates of geometrical form, and the bands are separated by skin. There is a notch in the last band for the tail, and the free inferior edges of the bands are everywhere fringed with silky hair. This elongated band structure is moved, to a certain extent, by two broad thin muscles, which are beneath it, on the back, and each of which divides, on approaching the shoulder, into two portions, one being attached to the bladebone, and the other to the occiput.
The ear is hidden by hair, and is small; so also is the eye, which is black. The nostrils open downwards, at the inferior border of a large cartilage. The mouth is small, and there are eight teeth on both sides in both jaws. They are simple molars, and are separate and cylindrical. The head is large behind, and the jaws come almost to a point, and the lower has a long ascending ramus. A great passage for the spinal cord, and the two processes on the frontal bone, add to the curious appearance of this “bumpy” skull. The pelvis is remarkable in its structure, and is open in front.
Some of these animals have the bands of the armour not attached, as has been mentioned, to the muscles of the back and to the head, but have them adherent to the skin of the back to the edge; and the sides and under part of the body are then covered with woolly hair. These are the largest animals of the two, and are found in Bolivia. The others are from Mendoza and Chili. These curious animals live, partly, mole-like lives.
From what may be gleaned by reading the previous pages about the Edentates, it will appear that the order is a very remarkable one, and that it is interesting on account of the different external appearance of the species, their diverse modes of life, and singularly restricted localities. Evidently, there has been much degeneration in some of the anatomical characters of many of the species, and especially in those whose foot bones and neck vertebræ have joined more or less. The singular resemblance which some species present, in various points of their anatomy, to the lower animals, is very interesting, as is also their wonderful relation, in points of structure, with a number of extinct Edentata, most of which were gigantic.
The Edentata, called also Bruta by Linnæus, form an order, the characters of which are, that there are teeth of one or two kinds all very similar, and often wanting. The incisors are not developed except in one group, and the rest have either molars which are separate, and numerous and simple, or there are none. The extremities are clawed, and the tongue is more or less elongated. The great groups of this order are the Tardigrada, or slow movers, which have a short face, long limbs, and small tail, and the body is covered with crisp hair; and the Effodientia, or diggers, which have long faces and worm-like tongues, with short limbs.
The Sloths form the only family of the Tardigrada, and the Effodientia are divided into the genera Manis, the scaly Ant-eaters; Dasypus, the Armadillos; Chlamydophorus, the Pichiciagos; Orycteropus, the Ant-Bears; and Myrmecophaga, the American Ant-eaters. The Sloths form three genera—Cholœpus, Bradypus, and Arctopithecus. Amongst the Ant-eaters, the genus Manis may stand alone. The genus Dasypus may be divided, for the sake of convenience, into the subdivisions Priodontes, Kabassous, Euphractes, Cachicames, and Tolypeutes. The other genera need no subdivision.
The fossil Edentata are mostly gigantic, and formerly lived in Europe and in the Americas. The European kinds would, were they now living, belong probably to the group of Pangolins, and they are placed in the extinct genera Pervatherium, Macrotherium, and Ancylotherium. In the Pliocene deposits of North America, there are large Edentates belonging to the genus Morotherium, and the previous Miocene deposits contain Moropus. The later, or Post-Pliocene strata of North and South America, contain species of Mylodon and Megalonyx, Megatherium, Scelidotherium, Cœlodon, and Sphenodon; they constitute a group of Terrestrial Sloths—the Gravigrada. In Cuba, the fossil huge Gravigrade Sloths are of the genera Megalocnus and Myomorphus. The Armadillo group are found fossil in South America, and the genera are Chlamydotherium, Euryodon, Heterodon, Pachytherium, and Schistopleuron. The modern genera are found with these, and the gigantic Armadillo-like animal, the Glyptodon, lived contemporaneously with the others, and possessed many strange peculiarities in its skeleton. The Ant-eaters are represented by a fossil form called Glossotherium. The oldest Edentates of the American Continent are found in North America, unless there is a Miocene group of them in South America, which is by no means an improbable supposition. The European Ant-eaters now found fossil lived in the Eocene, Miocene, and Pliocene ages.
With regard to the discovery of recent and closely-allied species of Manis, in South Africa and Hindostan, it may be said that they are relics of the old forms of the intermediate and now sunken land, between Eastern Africa and India, which existed before the last upheaval of the Himalayas. The evident structural affinity between the Effodient Edentata of South America and Africa, although the genera are different, adds to the interest of the corresponding, and in some instances greater, resemblance of many African and South American fresh-water fish and plants. The geologist looks back in the remote ages of the globe, when the great land surfaces and seas of the world were rather across the earth than in their present longitudinal position, in order to explain this remarkable similarity.
P. MARTIN DUNCAN.
GREAT KANGAROO.
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