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.