| OCR Text |
Show oR8 ISLAND LIFK [ P A 11'1' H. ------------------------- Tertiary times the islan d was usua llY as lam..., e as, and often probably much larger than, it is now. Biological featu?·es of Madagasca.T.-Madagascar p~sses~es ~n excecdm. O'ly n.c h and b eaUtl' fL 1 1 f:·c l.Una and flora ' nvalhnOb ' m some gro~::~u ps most trop1·c a1 coun t n.· es of equal extent ~ and ev. en when poor in species, of surpassing interest fro~ the smgulanty, the isolation, or the beauty of its forms of hfe. In order to exhibit the full peculiarity of its natural history and the nature of the problems it offers to the biological stude~t, we mu~t o·ive an outline of its more important animal forms m systematic b order. . . Jvfammalia. -Madagascar possesses no less than S1x~y-s1x species of mammals-a certain proof in itself that the Island has once formed part of a continent; but the character of these animals is very extraordinary and very differ~nt. from t~e assem blacre now found in Africa or in any other ex1stmg contment. Africa is now most prominently characterised by its monkeys, apes, and baboons ; by its lions, leopards, and hyrenas; by its zebras, rhinoceroses, elephants, buffaloes, giraffes, and numerous species of antelopes. But no one of these animals, nor any thing like them, is found in Madagascar, ancl thus .our fi.rst impression would be that it could never have been umted w~th the African continent. But, as the tigers, the bears, the tap1rs, the deer, and the numerous squirrels of Asia are equally absent, there seems no probability of its having been united with that continent. Let us then see to what groups the mammalia of Madagascar belong, and where we must look for their probable allies. First and most important are the lemurs, consisting of six genera and thirty-three species, thus comprising just half the entire mammalian population of the island. This group of lowly-organised and very ancient creatures still exists scattered over a wide area ; but they are now here so abundant as in the island of Madagascar. They are found from West Africa to India, Ceylon, and the Malay Archipelago, consisting of a number of isolated genera and species, which appear to maintain their existence by their nocturnal and arboreal habits, ami by haunting dense forests. It can hardly be said that the <;HAP, XlX.J TilE MADAGASCAR GROUP. 389 African forms of lemurs are more nearly n,llied to those of Madagascar than arc the Asiatic, the whole series appearing to be the disconnected fragments of a once more compact and extensive group of animals. Next, we have about a dozen species of Insectivora, consisting of one shrew, a group distributed over all the great continents ; and five genera of a peculiar family, Centetidre, which family exists now here else on the globe except in the two largest \Vest Indian Islands, Cuba and Hayti, thus adding still further to our embarrassment in seeking for the original horne of the Madagascar fauna. We then come to the Caruivora, which are represented by a peculiar cat-like animal, Cryptoprocta, forming a distinct family, and having no allies in any part of the globe; and eight civets belonging to four peculiar genera. Here we first meet with some decided indications of an African origin ; for the civet family is more abundant in this continent than in Asia, and some of the Madagascar genera, seem to be decidedly allied to African groups-as, for example, Euplercs to Suricata and Crossarchus.1 The Rodents consist only of four rat~ and mice of peculiar genera, one of which is said to be allied to an American genus ; and lastly we have a river-hog of the African genus Potamo· chrerus, and a small sub-fossil hippopotamus, both of which being semi-aquatic animals might easily have reached the island from Africa, by way of the Comoros, without any actual land-connection. Reptiles of Madagascar. -Passing over the birds fur the present, as not so clearly demonstrating land-connection, let us see what indications are afforded by the reptiles. The large and universally distributed family of Colubrine snakes is represented in Madagascar, not by African or Asiatic genera, but by two American genera-Philodryas and Heterodon, and by Horpetodryas, a genus found in America and China. The other genera are all peculiar, and belong mostly to widespread tropical families; but two families-Lycodontidre and Viperid~:e, both abundant in Africa and the Eastern tropics-are absent. Lizards are mostly represented by peculiar genera of African or 1 See Dr .• J. E. Gray'B "Hevisiun of tl10 Viverrida:,'· in F1·oc. Zool. Soc. 186 ~, p. 507. |
