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DISTRIBUTION OF MONKEYS AND LEMURS
Section I.—Introductory Remarks
Having now completed the discussion of the great Zoological Regions of terrestrial and marine mammals and their leading peculiarities, it is proposed to take the subject in another way, and considering the Orders, or great primary groups of mammals, one after the other, to sketch out the mode in which their leading forms are distributed over the surface of the world. We shall then see whether the conclusions thus arrived at appear to lead to similar results to those attained by making geographical divisions our primary subject of study. In doing this it will be more convenient to take the most highly organized groups of mammals first, and to descend gradually to the lowest, reversing the arrangement used in the previous chapters of this work. The divisions and names now employed are taken from the last edition of the "List of Ver- tebrated Animals in the Zoological Society's Gardens," (1896), but do not differ materially from those used in Flower and Lydekker's "Mammals Living and Extinct," which we have hitherto mainly followed. These divisions, commonly called "Orders," are fourteen in number, as follows:—
Section II.—General Distribution Of The
The Order of Quadrumana, or Monkeys, of which about 200 species are now recognized, is generally divided by zoologists into four families: (1) the Simiidm or Apes, (2) the Cercopithecidm or Old-World Monkeys, (3) the Cebidm or New-World Monkeys, and (4) the HapalicUe or Marmosets. Of these families the two first are exclusively inhabitants of the tropical or sub-tropical districts of the Old World, while the two last are as severely restricted to the hotter portion of the New World, and form, in fact, two of the most characteristic groups of the Neotropical Region. We thus see that the division of the Quadrumana into families according to their structure is in complete accordance with the distinctness of the geographical areas in which they are found.
The two first and highest families of Monkeys, it should be remarked, are much more nearly allied to one another than they are to the two families which inhabit the New World. They are sometimes called "Catarrhines," on account of the narrowness of the nasal septum and the consequent downward direction of the nostrils. They all
VI. RODENTIA. VII. Hyraces.
agree together in possessing the same number of teeth and the same general structure of these organs as Man, who, if considered only from a material point of view, must certainly be referred to the same group of animals.
On the other hand, the two families of Quadrumana belonging to the New World have each of them a dentition peculiar to themselves and different from that of the Catarrhine Monkeys, to which they are inferior in every point of organization. The first of these two families, the Cebidm, have been designated " Platyrrhines," in reference to the broad septum which separates the nostrils from each other, and thus distinguishes them from the Catarrhine Monkeys of the Old World. The second family of New World Monkeys, the Marmosets, are unquestionably the lowest of the Quadrumana, and have some superficial resemblance to the Squirrels and other Rodents.
Section III.—Distribution Of The Old World
The Catarrhine Monkeys, as already stated, are restricted to the Old World, and in present days, as we shall see, mainly to the tropics, though a few species are found farther north, and other forms, now extinct, have left their remains in the tertiary and post-tertiary formations of more temperate countries.
The Catarrhine Monkeys form two families, the Simiidm or Man-like Apes, and the CercojrithccicUe or Monkeys proper. The Man-like Apes, in the present condition of the world's surface, are confined entirely to the equatorial Regions of Africa and Asia. They are usually referred to three genera: (1) Anthropopithecus, which embraces the Black Apes of tropical Africa, (2) Simia, which contains the Brown Apes of tropical Asia, and (3) Hylobates, which contains the Gibbons, likewise restricted to tropical Asia.
It has been a subject of much discussion among zoologists as to which of these three forms of Simiine life comes nearest to man in structure. Some have advocated the claims of the Orang to this distinction, but it is now generally held that his black cousins of the Ethiopian Region ought to be placed at the head of the series. It has likewise been maintained by some authorities that in certain respects the Gibbons (Hylobates) come nearer to man than either of the above-mentioned forms, but this opinion has not met with general support. We will therefore commence our survey of the distribution of the Anthropoid Apes with their African representatives, the Chimpanzee and the Gorilla.
The Chimpanzee (Anthropopithecus troglodytes) is certainly widely spread over tropical Africa, but we have not as yet acquired sufficient details as to the exact limits of its distribution. Nor are naturalists at all agreed as to whether one or more species are comprehended under the name of Chimpanzee, though it is generally allowed that the Bald-headed Chimpanzee (A. calvus), a well-known specimen of which lived in the Zoological Society's Gardens for many years, must be considered distinct from the ordinary A. troglodytes. But in examining the distribution of the Chimpanzee it is hardly necessary to seek to determine this vexed question more nearly.
Commencing on the western coast of Africa, the range of the Chimpanzee appears to begin with the wooded districts somewhat to the south of the river Gambia, and to continue all down the coast-region into Angola, south of the Congo. Here the dry and open country of south-west Africa commences, and, as the Chimpanzee is essentially a forest animal, it could not be expected to be met with farther in this direction. The Chimpanzee in its inland range appears to extend over the whole wooddistrict of the great Congo valley, and in the Niam-Niam country, perhaps, passes over into the basin of the Nile. It was heard of by Livingstone in the forests on the western side of Lake Tanganyika where it is said to be called "Soko," and the late Emin Pasha sent to England the skull of a Chimpanzee stated to have been shot by himself near Lake Albert Nyanza, which seems hardly to differ from the West African form. Whether Emin Pasha's assertion that the Chimpanzee occurs in Uganda and Unyoro up to 32° E. lat. is correct is very doubtful. It seems to have been made on native authority, and has not, so far as we are aware, been corroborated by more recent travellers. But as regards its existence in the Niam-Niam country we have Emin Pasha's express statement that he received a living specimen of the Chimpanzee as a present from one of the chiefs of that nation.1
The Gorilla (A. gorilla), which by some authors is referred to a different genus from the Chimpanzee although its general structure is not materially different, is confined to a very much more limited area than that of its smaller brother (A. troglodytes). So far as we know at present, it seems to be entirely restricted to Gaboon and the adjacent districts of French Congo. Whether the extraordinary accounts formerly given of the strength and
1 "Emin Pacha in Central Africa," p. 355.