THE KANGUROO.
发布时间:2020-06-19 作者: 奈特英语
Macropus Major. Shaw.
The very peculiar structure from which the Marsupial animals derive their name has been regarded by almost every naturalist who has written on the subject as so essential a deviation from the common type, that, setting aside all considerations of form or habits, and regardless even of those technical characters on which so much reliance is usually placed, they have for the most part agreed in uniting under the same family designation every animal in which it occurred. This peculiarity consists in a folding or doubling of the skin and its appendages beneath the lower part of the belly in the females, in such a manner as to form an open pouch or[156] bag, in which the young are contained from a very early period, in which the process of suckling takes place, and in which, even for some time after they have acquired sufficient size and strength to leave it, the little ones continue to take refuge.
But the presence of this one anomalous characteristic is accompanied by so many striking discrepancies in other parts, that, limited as this tribe is in number, most of the principal forms of Mammalia find analogous representations among its groups. Thus the Opossums exhibit characters in some measure intermediate between the Quadrumana and the Carnivora, to which latter the Dasyuri, another Marsupial group, closely resembling the Civets in form and habits, approach very nearly; while the herbivorous races of the tribe might occupy a station between the Rodent and Ruminant Orders, with each of which they exhibit various degrees of relationship. This want of uniformity in the essential parts of their organization necessarily gives rise to much difficulty in determining their position in the system. The mode of classification now most generally followed is perhaps, under all the circumstances, the best that could at the present moment be adopted; although it must be owned that the purely herbivorous species arrange themselves with a very ill grace under a subdivision of the order Carnivora. Placed, however, as they are at the end of that order, and immediately before the Rodentia, the regular gradations from the type of the former to that of the latter, which occur in their different groups, become most distinctly manifest.
With the exception of the Opossums, which are natives of America, the tribe is peculiar to New Holland and its[157] appendages, and to some of the islands which form the great chain of connexion between that insular continent and South-eastern Asia. The former is, however, their head quarters, and the species which are found beyond its limits are few in number compared with those which people its territory, and, what is more remarkable, people it to the exclusion of nearly all the other Mammalia; the dog alone, the universal concomitant of man, and one or two species of rats, disputing with them their title to its exclusive possession; for those paradoxical creatures, the Ornithorhynchus and Echidna, if really mammiferous, approximate closely in structure to the Marsupial tribe.
The largest of these animals are the Kanguroos, whose generic characters we shall now proceed to describe. Their teeth are only of two kinds, the canines being altogether wanting. The incisors are six in the upper jaw, and two only in the lower; the former short, and arranged in a curved line, and the latter long, pointed, closely applied to each other, and directed forwards. The molars are separated from the incisors by a considerable vacant space, and are five in number on each side of each jaw. The most remarkable peculiarity in the external form of these animals consists in the extreme disproportion of their limbs, the anterior legs being short and weak, while the posterior are extremely long and muscular. The tail too is excessively thick at its base, of considerable length, and gradually tapering; and this singular conformation enables it to act in some measure as a supplemental leg, when the animal assumes an erect or nearly erect posture, in which position he is supported as it were on a tripod by the joint action of[158] these three powerful organs. By means of this combination they will, when flying from danger, take a succession of leaps of from twenty to thirty feet in length and six or eight in height; but even in their more quiet and gradual mode of progression they also make use of their tail in conjunction with their four extremities. The fore feet are furnished with five toes, each terminating in a moderately strong and arcuated claw. The hinder extremities, on the contrary, have only four toes, the two interior of which are united together so as to form the appearance of a single one furnished with two short and feeble claws; the third is long, of great strength, and terminated by a large and powerful claw having the form of a lengthened hoof; and the fourth, the most external of the series, is similar in character to the third, but of much smaller dimensions. The head and anterior part are small and delicate, and appear quite disproportioned to the robust posterior half of the body; and this disproportion is equally striking, whether the animal assumes an erect position or crouches forwards upon all fours. In either case the whole extent of the soles of the posterior feet, which are of great length, is applied to the surface of the ground. Although differing from all the Rodent animals in the number of the cutting teeth of the upper jaw, the Kanguroo has the deep fissure in the upper lip, with which nearly all that order are furnished, and of which the hare offers a familiar and proverbial instance.
These singular animals were among the first fruits which accrued to natural history from the discovery of New South Wales, a country which has since proved so fertile in new and remarkable forms both of the animal[159] and vegetable creations. Their natural habits in a wild state are still, however, very imperfectly known. They appear to live in small herds, perhaps single families, which are said to submit to the guidance of the older males, and to inhabit in preference the neighbourhood of woods and thickets. They are, as might be inferred from the small size of their mouths and the peculiar character of their teeth, purely herbivorous, feeding chiefly upon grass and roots. Their flesh is eaten by the colonists, by whom it is said to be nutritious and savoury, an assertion which is confirmed by those who have partaken of it in England. In order to procure this they are frequently hunted in their native country; but the dogs who are employed in this service sometimes meet with dangerous wounds, not only from the blows of their powerful tail, which is their usual weapon of defence, but also from the claws of their hind feet, with which they have been known to lacerate the bodies of their assailants in a shocking manner. But, unless when thus driven to make use of such powers of self-defence as they possess, they are perfectly harmless and even timid; and, when domesticated, are not in the least mischievous. In several collections in this country, and particularly in the Royal Park at Windsor, from which the specimens in the Menagerie were obtained, they have become almost naturalized, and appear to be but little affected by the change of climate. When confined in a small enclosure, they uniformly make their path round its circuit, seldom crossing it or passing in any other direction except for the purpose of procuring their food. Their whole appearance, and especially their mode of progression, is singularly curious and even to a certain extent ludicrous.
[160]
Modern naturalists have attempted to distinguish several species among the Kanguroos; but as the characters on which these are founded consist merely in difference of size and slight modifications of colour, a much more complete acquaintance with them than we yet possess is requisite before they can safely be adopted. Our specimens are of a brownish gray above, somewhat lighter beneath, with the extremity of the muzzle, the back of the ear, the feet, and the upper surface of the tail, nearly black, and the front of the throat grayish white. Since they have been confined in the Menagerie, the female has once produced young; a circumstance by no means unfrequent even in this country among those which are less restricted of their liberty and are suffered to roam at large in a meadow or a park. They are fed, like the domesticated Ruminants, upon green herbage and hay; and are extremely tame and good tempered.
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