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THE GEOGRAPHICAL DISTRIBUTION OF ANIMALS.

by the, world at large as a mere organizer of good deeds, the deepest interior life which he himself lives, and which he most values, is mulcted of its most precious moments and its rarest pleasures, in order to supply that monotonous strain of energetic work from which the world reaps so great a gain. Even the crowds who on Tuesday followed the remains of Mary Carpenter to her grave, and who loved and honored her for her long life of unselfish work and unwearied sympathy, probably never knew how much she must have sacrificed in order to be what she was. The great doers have at least this advantage over those whose chief fascination for their fellow-men consists solely in what they are, - that in this world at least, and in many departments of life, they refrain from being all that they otherwise might have been, for the sake of those for whom they could not in that case have achieved all they have achieved. In short, they give up an inward life of their own to redeem the inward life of others; and surely they will yet receive again with usury more than all they have so given up.




From The Popular Science Review.

NOTES ON THE GEOGRAPHICAL DISTRIBUTION OF ANIMALS.

BY W. F. KIRBY.

ASSISTANT NATURALIST, MUSEUM, ROYAL DUBLIN SOCIETY.

The study of the geographical distribution of living and extinct organisms has recently become one of the most important branches of philosophical natural history, from the light which it throws both on the former condition of the earth, and on the greatest scientific question of the day, namely, that of the origin of species. The geographical distribution of animals has lately received much attention, the most important contribution to the subject being a large work by Mr. A. R. Wallace; but in the present paper we propose to bring together such observations as may prove interesting, either from their importance or from their having been less fully discussed elsewhere.

Most naturalists are now agreed in recognizing six main regions of geographical distribution, as originally proposed by Dr. Sclater, viz., the Palæarctic, Ethiopian (or African), Indian (or riental), Australian, Neotropical (or tropical American), and Nearctic (or North American) regions. The Palæarctic region includes Europe, north Africa, the northern half of Arabia, and the whole of western and northern Asia, as far as the Indus and Himalayas, and a line drawn eastwards, running south of Thibet and Mongolia, and somewhat north of Formosa. The Indian region includes, besides south Asia, the large islands of Borneo, Java, Sumatra, and the Philippines; but the islands further to the east belong to the Australian region. The Neotropical region includes the West Indies, Central and South America, and the south of Mexico; the remaining regions require no further explanation.

Although these regions are generally recognized as natural, we must not consider the divisions between them as hard and fast lines, except that between the Indian and Australian regions, where the island of Celebes is almost the only debatable ground. Indeed, the fauna of much of the west coast of America, especially that of California and Chili, exhibits such marked affinities with that of the Palæarctic region, that these countries have been regarded by some writers rather as outlying districts of the latter than as biological portions of the continents to which they actually belong. It is also to be observed that this division of the world into six main regions is more applicable to some groups of animals and plants than to others. Various attempts have been made to subdivide the regions, but though some subdivisions, such as the Mediterranean subregion, are eminently natural, our knowledge of the natural productions of most of the regions is not yet sufficiently exact to allow of their being divided in such a manner as to gain the general assent of naturalists.

Owing to the much greater competition of rival forms in large continents, the larger and more highly developed forms always appear to have originated and been brought to relative perfection on the greatest continuous districts of land. But notwithstanding the frequent alterations of level during geological ages, which have constantly united or separated various portions of the earth's surface, yet it appears that the largest masses of land, though differing in outline and continuity, have always occupied nearly the same places; that is, it is more probable that the contour of former continents has been changed by gradual increase or diminution, than that a whole continent should be submerged or elevated de novo. It also appears that the northern hemisphere, and more especially the Palæarctic region, has