OCR Text |
Show 6 ISLAND LIFE. (PART I. almost identical in climate and in luxuriance of vegetation, but their animal life is totally diverse. In the former we have tapirs, sloths, and prehensile-tailed monkeys ; in the latter elephants, antelopes, and man-like apes; while among birds, the toucans, chatterers, and humming-birds of Brazil are replaced by the plantain-eaters, bee-eaters, and sun-birds of Africa. Parts of South-temperate America, South Africa, and South Australia, correspond closely in climate; yet the birds and quadrupeds of these three districts are as completely unlike each other as those of any parts of the world that can be named. If we visit the great islands of the globe, we find that they present similar anomalies in their animal productions, for while some exactly resemble the nearest continents others arc widely different. Thus the quadrupeds birds and insects of Borneo correspond very closely to those of the Asiatic continent, while those of Madagascar are extremely unlike African forms, although the distance from the continent is less in the latter case than in the former. And if we compare the three great islands Sumatra, Borneo, and Celebes-lying as it were side by Ride in the same ocean-we find that the tvvo former, although furthest apart, have almost identical productions, while the two latter, though closer together, are more unlike than Britain and Japan situated in different oceans and separated by the largest of the great continents. These examples will illustrate the kind of questions it is the object of the present work to deal with. Every continent, every country, and every island on the globe, offer similar problems of greater or less complexity and interest, and the time bas now arrived when their solution can be attempted with some prospect of success. Many years study of this class of subjects bas convinced me that there is no short and easy method of dealing with them ; because they are, in their very nature, the visible outcome and residual product of the whole past history of the earth. If we take the organic productions of a small island, or of any very limited tract of country such as a moderate-sized country parish, we have, in their relations and affinities-in the fact that they are there and others arc CHAP. I,] INTRODUCTORY. 7 not there, a problem which involves all the migrations of these species and their ancestral forms-all the vicissitudes of climate and all the changes of sea and land which have affected those migrations-the whole series of actions and reactions which have determined the preservation of some forms and the extinction of others,-in fact the whole history of the earth, inorganic and organic, throughout a large portion of geological time. We shall perhaps better exhibit the scope and complexity of the subject, and show that any intelligent study of it was almost impossible till quite recently, if we concisely enumerate the great mass of facts and the number of scientific theories or principles which are necessary for its elucidation. We require then in the first place an adequate knowledge of the fauna and ·flora of the whole world, and even a detailed knowledge of many parts of it, including the islands of more special interest and their adjacent continents. This kind of knowledge is of very slow growth, and is still very imperfect; 1 1 I cannot avoid here referring to the enormous waste of labour and money with comparatively scanty and unimportant results to natural history of most of the great scientific voyages of the various civilized governments during the present century. All these expeditions combined have done fat· less than private collectors in making known the products of remote lands and islands. They have brought home fragmentary collections, made in widely scattered localities, and these have been usually described in huge folios, whose value is often in inverse proportion to their bulk and cost. The same species have been collected again and again, often described several times over under new names, and not unfrequently stated to be from places they never inhabited. The result of this wretched system is that the productions of some of the most frequently visited and most interesting islands on the globe are still very imperfectly known, while their native plants and animals are being yearly exterminated, and this is the case even with eountries under the rule or protection of European governments. Such nre the Sandwich Islands, Tahiti, the Marquesas, the Philippine Islands, and a host of smaUcr ones ; while Bourbon and Mauritius, St. Helena, and several others~ have only been adequately explored after an important portion of their productions has been destroyed by cultivation oi: the reckless introduction of goats and pigs. 'l'he employment in each of our possessions, and those of other European powers, of a resident natura1ist at a very small annual expense, would have done more for the advancement of knowledge in this direction than all the expensive ~xpeditions that have again and again circumnavigated the globe. |