MAMMALIA. The animal kingdom was arranged by Cuvier into four great subdivisions, —Vertebrate, Mollusca, Articulata, and Radiate. The Articulata has since been greatly subdivided, and the limits of two of the other subdivisions have been slightly altered. Vertebrate animals comprise four distinct classes, some of which, viz. fishes and reptiles, have blood nearly the temperature of the water or air in which they live, whilst the others, viz. the birds and mammals, are warm blooded. The mammals, which are here to be noticed, are warm - blooded, vertebrate, viviparous animals, and are distinguished from birds, as well as from the other vertebrate animals, by the possession of mammary glands, secreting milk for the nourishment of their young, and terminating outwardly in all (except in one or two) by teats. They are also distinguished by a covering of hair, except whales, but even the foetus of whales has some tufts of hair. Most mammals have four limbs, from which they were formerly termed quadrupeds, but that term has been discontinued, as it is not applicable to the Cetacew. In cold climates, several animals pass the winter in a state of torpidity ; and even in India certain bats and hedgehogs, and perhaps some rats, are more or less torpid during the cold season. Two species of bears found in the Him alaya retire to their caves during winter, and are rarely or never seen from the month of December till the end of March.
The animals of the East Indies in this branch of natural history have been described by several eminent men. In 1830-34 Dr. J. E. Gray published Illustrations of Indian Zoology, chic fly sel ee ted from a c011ection. made by Major-General Hardwicke Colonel Sykes published a list of the animals observed by him in the Dekhan ;- Sir Walter Elliot in 1839 gave a Catalogue of the Maminalla of the Southern Mahratta Country; Mr. Hodgson published several lista of the Manimalia of Nepal ; Colonel Tickell gave a detailed History of a few Animals ; Major Hutton recorded 'some facts on the Mammals of Afghanistan ; Mr E. L. Layard, Dr. Kelaart (in his Prodromus Floras Zeylaniae 1852), Dr. Templeton, and Sir J. E. Tennent, almost exhausted the snbject of the Fauna of Ceylon ; Dr. Horsfield (1824, 1851) and Sir T. S. Raffles were amongst the first to describe the animals of the Eastern Archipelago; and Professor Bikmore and Mr. A. Russell Wallace haVe" recently extended their predecessors' researches. Mr. Wallace in 1869 and 1872 Wrote on the Malay Archipelago, and in 1876 and 1880 on the Geo graphical Distribution of Animals. In 1846-47
Dr. Cantor furnished a valuable list of the Mpan malia of the Malay PeninsulaDr.-T. C. Jerdon in 1864 published the Mammals of India ; and the labours of all these zoologists were reviewed by Mr. Blyth, curator of the Bengal Asiatic Society s Museum, in the scientific journals of the day. Colonel A. C. MacMaster, of the Madras army, in 1870 gave to the public his interesting Notes on Jerdon's Mammals, and since then; in 1874, Dr. Jerdon's book has been reprinted. In 1876, Captain J. H. Baldwin described the Large and Small Game of Bengal and the N.W, Provinces. In the same year (1876), W. T. Blau ford, in the second volume of his book on Eastern Persia, described its Zoology and Geology; also those of Abyssinia, in 1879; and in the same year he gave the scientific results of the second Yarkand mission. In the Calcutta Museum published a Catalogue of its Mammalia ; in 1884 Mr. R. A. Stcrndale's Natural History of the Mammalidof India and Ceylon was printed ; and it may be added that Sir Joseph Fayrer has written on the Tiger. The Journal of the Bengal Asiatic Society contains numerous contributions from other able zoologists. . .
Classiflcation.—The animal kingdom has been arranged by learned naturalists in varied modes. Mi. A. R. Wallace, one of the ablest of the present day, in his Geographical Distribution of Animals, i. p.. 85, gives the following classifica tion as according with the views of Professors Huxley (1869) and Flower (1870):— Di. Jerdon arranged mammals into Placental, or those in which the foetus is' nourished in the maternal uterus by means of a placenta ; and Implacental or Marsupial, or those in which the young foetus is expelled at a very early period, and maintained, in a pouch, firmly attached to a nipple. The implacental or marsupial animals occur in the Australian region, and a few in America.
Mr. Blyth arranged the Placental mammals into— I. Typodontia, animals with the typical forms of teeth developed, and include man, monkeys, bats, carnivorous animals, and shrews. The majority live on animal food.
II. Diplodontia, rarely more than two kinds of teeth, and include rats, squirrels, deer, sheep, cattle, the elephant, pig, horse, and the almost toothless ant-eater. They chiefly live on vege table matter.
III. Isodontia, teeth, when present, are all of one kind, and comprise the whales and porpoises.
The details of the above classification are thus shown— a. Placental mammals, foetus nourished in the uterus, through a placenta.