446 ISLAND LIFE 



Mr. Baker's Flora for Mauritius and the Seychelles, and 



frora an estimate by M. Frappier of the flora of Bourbon 

 given in Maillard's volume already quoted : — 



Mauritius, d-c. Bourbon. 



Ferns 168 Ferns 240 



OrcMdese 79 OrchidccC 120 



Gramineos 69 Gramine;ie 60 



CyperaeesB 62 Compositfe 60 



Rubiacese 57 Leguminosre 36 



Euphorbiacete 45 Rubiacese 24 



Composite 43 Cyperaceae 24 



LegiiminosEe 41 Euphorbiaceai 18 



The cause of the great preponderance of ferns in oceanic 

 islands has already been discussed in my book on Tropical 

 Nature ; and we have seen that Mauritius, Bourbon, and 

 Rodriguez must be classed as such, though from their 

 proximity to Madagascar they have to be considered as 

 satellites to that great island. The abundance of orchids, 

 the reverse of what occurs in remoter oceanic islands, may 

 be in part due to analogous causes. Their usually minute 

 and abundant seeds would be as easily carried by the wind 

 as the spores of ferns, and their frequent epiphytic habit 

 affords them an endless variety of stations on which to 

 vegetate, and at the same time removes them in a great 

 measure from the competition of other plants. When, 

 therefore, the climate is sufficiently moist and equable, and 

 there is a luxuriant forest vegetation, we may expect to 

 find orchids 23lentiful on such tropical islands as possess 

 an abundance of insects adapted to fertilise them, and 

 which are not too far removed from other lands or conti- 

 nents from which their seeds might be conveyed. 



Coiiduding Remarks on Madagascar and the Mascarene 

 Islands. — There is probably no portion of the globe that 

 contains within itself so many and such varied features of 

 interest connected with geographical distribution, or which 

 so Avell illustrates the mode of solving the problems it 

 presents, as the comparatively small insular region which 

 comprises the great island of Madagascar and the smaller 

 islands and island-groups which immediately surround it. 

 In Madagascar we have a continental island of the first 

 rank, and undoubtedly of immense antiquity ; we have 

 detached frasments of this island in the Comoros and 



