address; and the animals are said to introduce it into the hollows and fissures of trees, in order to hook out eggs, which they relish as food. The naked portion of the prehensile tail of the Australian phalangers is also highly sensitive.

In all the ape and monkey tribes, the arms are proportionally longer than in man: but there is considerable difference among them. In the orang and gibbons, the arms are so long that when the animals stand in an erect position they nearly touch the ground; the hands too are of extreme length, while the hinder limbs are greatly abbreviated; but, in the baboons, which are far more terrestrial in their habits, and never attempt to assume an erect posture, there is more equality between the anterior and posterior limbs. In many, the fore-arm greatly exceeds the upper-arm, or humerus, in length, and of the two bones of the fore-arm that called the radius, on which the pronation and supination of the hand depend, is the stoutest, a condition the reverse of that which we find in the human skeleton. As a rule the blade-bones are far more lateral than in man, and the clavicles or collar-bones are shorter and straighter. Such, then, are

the rude hands or graspers of the ape tribe; they are not destined for "the purposes of ingenuity and art; " they are not organs corresponding to a highly developed intellect; they are not the servants of mind, but are rather "adaptations of the feet to the branches on which the animals climb and walk." Nevertheless the arm and hand of these creatures approximate nearer to those of the human subject than is found in any other quadruped. It has been observed as a rule, "that all animals which freely use the forepaws, either for holding, digging, climbing, or flying, and which have the fore-arm in a greater or less degree capable of revolving, possess a clavicle more or less developed." In some animals that dig, as the mole, it is of great thickness and strength, while in the cat tribe it is a mere rudiment imbedded in the muscles of the shoulder. In the bat it is well formed. The bat is expressly organized for flight; the bones of the arms, and also of the fingers of the hands, are greatly elongated, and, like the strips of whalebone in an umbrella, serve as stretchers to an extensive and very delicate membrane, which can be folded up or unfolded at pleasure. The sensibility of these

membranous wings is extreme; they are capable of appreciating the vibrations of the atmosphere, its currents, its quiescence, and its more subtile conditions, with such refined nicety, that if the animal's eyes be covered up, it will direct its course, avoiding every obstacle in its way with the most surprising address. The thumb of the bat is short and free, and armed, as are the hind toes, with a hooked claw, enabling the creature to climb and shuffle itself along.

The

How different the structure of these membranous organs of flight from the stout, short, spade-like paws of the burrowing mole; and how wisely has Providence assigned to each creature that modification of structure which is in due accordance with its instincts! very form of the mole shows it to be a burrower; it lives, it rears its young, and pursues its prey under ground, only occasionally visiting the surface; it works out its mines and galleries with marvellous ease and celerity, extending them in various directions in quest of worms, which constitute its principal food. If we look at its fore-paws we are at once struck with their strength, breadth, and solidity; the fingers are short and thick, com

pacted together, and armed with nails of great size, which are concave below and pointed at the tip; in their ordinary position the palms are turned obliquely outwards, so that in the act of scraping, the earth is thrown on each side of the animal. With these efficient instruments the bones and muscles of the arm and chest are in complete accordance: the bones of the arms are short, but very thick and solid, and the clavicles are almost in the form of a solid square. The power concen

trated in the anterior limbs of this animal is indeed enormous, and in this respect it perhaps excels every other burrower, even the armadillo and the chlamyphorus. In such

instruments we do not look for much sensibility, or the power of manipulation; the paws are scrapers or shovels, and their use forbids that they should be more.

From the burrowing mole let us turn to the arboreal sloth-arboreal, but in a dissimilar manner from the monkey. The sloth lives not upon, but suspended under, the branches, and travels along them in the dense forests of South America, with the back downwards. It lives a life of clinging; and to this end its limbs are structurally adapted. The arms are very long,

and the clavicles are doubly united to the blade-bones. The hand is a hook, (trebled in some species, doubled in another,) by means of which the animal suspends itself. The bones of the wrist are consolidated into a single piece, and the three (or two) fingers are short and arched inwards, the joints of the bones being adjusted upon a principle of unyielding strength. These fingers are furnished with enormous curved claws, or hooks, alone projecting from the undivided skin, which enshrouds together all the rest, both fingers and wrist. Hence, on looking at the clingers of the sloth, it would seem as if these claws alone constituted the digital portion. They can only move altogether; and, in their ordinary state, they are drawn forcibly towards the palm by the action of elastic ligaments, and require the voluntary exertion of the extensor muscles to unclose them; and this being discontinued, the elastic springs again draw them to the palm. In clinging, therefore, whether during repose or while travelling along, the sloth has not to trust alone to the exertion of voluntary muscles for its safety. The ligaments, ever in operation, are sufficiently tense to counteract the tendency of the body's weight to relax them. The long and