410 



ISLAND LIFE. 



[part II. 



situated about fourteen miles north-east of Mauritius, possesses 

 a snake which is not only unknown in Mauritius, but also in any 

 other part of the world, being altogether confined to this minute 

 islet ! It belongs to the python family, and forms a peculiar 

 and very distinct genus, Casarea, whose nearest allies seem to 

 be the Ungalia of Cuba and Bolgeria of Australia. It is hardly 

 possible to believe that this serpent has very long maintained 

 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 wdthout 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 the globe. 



On the same island there is a small lizard, Thyrus hoyeri, 

 also a peculiar species and genus, but this is recorded from 

 Mauritius and Bourbon as w^ell, though it appears to be rare in 

 both islands. As Bound Island is connected with Mauritius by 

 a bank under a hundred fathoms below the surface, it has pro- 

 bably 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 the 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 anoma- 

 lous external relations. It is characterised 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 w^orld, some decided South American 

 relations, while others point to Australia, or are altogether 

 isolated. 



