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Show 410 ISLAND LIFE. (PART II. situated about fourteen miles north-east of Mauritius, possesse_s a snake which is not only unknown in Mauritius, but al.so i~ any other part of the world;- being altogether confined to th1s mm~te islet! It belongs to the python family, and form~ a pecuhar and very distinct genus, Casarea, whose neares~ alhes. seem to be the·UnO'alia of Cuba and Bolgeria of Australia. It IS hardly 0 . . possible to believe that this serpent has very long mamtamed itself on so small an island; and though we have no record of its existence on Mauritius, it may very well have inhabited the lowland forests without being met with by the early settlers; and the introduction of swine, which soon ran wild and effected the final destruction of the dodo, may also have been fatal to this snake. It is, however, now almost certainly confined to the one small islet, and is probably the land-vertebrate of most restricted distribution on tho globe. On the same island there is a small lizard, Thyrus boyeri, also a peculiar species and genus, but this is recorded from Mauritius and Bourbon as well, though it appears to be rare in both islands. As Round Island is connected with Mauritius by a bank under a hundred fathoms below the surface, it has probably been once joined to it, and when first separated would have been both much larger and much nearer the main island, circumstances which would greatly facilitate tho transmission of these reptiles to their present dwelling-place. Flora of Madagascar and the Mascarene Islands.-The botany of the. great island of Madagascar has been perhaps more thoroughly explored than that of the opposite coasts of Africa, so that its peculiarities may not be really so great as they now appear to be. Yet there can be no doubt of its extreme richness and grandeur, its remarkable speciality, and its anomalous external relations. It is charac.terised by a great abundance of forest-trees and shrubs of peculiar genera or species, and often adorned with magnificent flowers. Some of these are allied to .African forms, others to those of Asia, and it is said that of the two affinities the latter preponderates. But there are also, as in the animal world, some decided South American relations, while others point to Australia, or are altogether isolated. CIIAP, XIX.] THE MADAGASCAR GROUP. 411 Among the most prominent characteristics of the Madagascar flora is the possession of a peculiar and isolated family, Chlrenacere, allied so mew hat to the balsams, but presenting very anomalous characters. It consists of four genem and a number of species all entirely confined to the island. They are handsome trees or shrubs, mostly with showy red flowers. One of them, Rhodolcerza altivola, is a semi-scandent shrub with magnificent campanur'ate flowers tho size of a camelHa and of a brilliant purple colour. The genus Chrysopia consists of large forest trees with spreading crowns adorned with umbels or corymbs of large purple flowers. It belongs to the Clusiacere, and is most nearly allied to the South American genus Moronobea. The Colvillea, a peculiar genus of Leguminosre, is a tree with splendid scarlet . flowers; and there are a large number of other peculiar genera more or less remarkable. Combretacere with splendid flowers abound in Madagascar itself, though they are rare in the Mascarene islands; while the Ravenala, or "traveller's tree;" the extraordinary lattice-leaved Ouvirandra; the Poinciana ngia, one of the most gorgeous of flowering trees; and the long-spurred Angrcecum sesquipedale, one of the most elegant and remarkable of orchids, are among its vegetable wonders. 1 Of the flora of the smaller Madagascarian islands we possess a much fuller account, owing to the recent publication of Mr. Baker's Flora of the Mcturitius and the Seychelles, including also Rodriguez. The total number of species in this flora is 1,058, more than half of which (536) are exclusively Mascarene-that is, found only in some of the islands of the Madagascar group, while nearly a third (304) are endemic or confined to single islands. Of the widespread plants sixty-six are found in Africa but net in Asia, and eighty-six in Asia but not in Africa, showing a similar Asiatic preponderance to what is said to occur in Madagascar. With the genera, however, the proportions are different, for I find by going through the whole of the generic distributions as given by Mr. Baker, that out of the 440 genera of wild plants 1 This sketch of the Flora of Madagascar is taken chiefly from a series of articles by M. Emile Blanchard in the Revue des Deux Mondes. Vol. cr. (1872). |
