Returning again to the Himalaya country, we encounter, in the plains south of this great chain, the Spotted Axis, so well-known from its beautiful markings, which resemble those of the fawn of our own fallow-deer. But it may be remarked that there are two or three species of spotted deer, and that they inhabit the plains of India--from the Himalayas southward to the Island of Ceylon. Ascending these great mountains, we encounter among their lower slopes another very singular species of cervine creature--the Musk Deer--which, though but little known, is one of the most interesting of its tribe; especially so, as it is from the secreting glands of this curious little animal that most of the celebrated perfume of commerce is obtained. Crossing the Himalayas, and advancing northwards, we find upon the plains of Central Asia a species of deer, known among the Tartars as Siaga, and to our own naturalists as the Tail-less Roe. Several species entirely unknown to scientific men will yet be discovered, when the immense steppes of Asia come to be explored by observers capable of describing and classifying. Like many another genus of animals, a complete monograph of the deer tribe would be of itself the labour of a life. CHAPTER TWENTY THREE. QUADRUPEDS WITH POCKETS. In the year 1711 was brought to France, from the Island of New Guinea, an animal of an unknown species, and one that was singular in many respects; but especially so, from the fact of its having a double skin, covering a part of its belly, and forming a sort of pocket or pouch. This animal was Le Brun's Kangaroo; very properly named after the naturalist who first described it, since it was the first of the marsupial or pouched animals known to the scientific world. The Opossums of America were afterwards scientifically described; but it is only of late years that the numerous species and genera of pouched animals--constituting almost the entire mammalia of the Australian world--have become generally known to Europeans. The peculiarity of the _pouched_ animals is in reality the _pouch_, common to all of them. Otherwise they differ in many respects--some being carnivorous, others graminivorous, others insectivorous, and so on. In fact, among them we have forms analogous to almost all the different groups of ordinary mammalia. Some naturalists have even classified them in the different groups, but with little success; and it is perhaps better to keep them together, retaining the "pouch" as the common characteristic.