— S31 — 



jfise ot' very little more than this, say 400 feet, a mere 

 trifle in ooruparison with the height of the mountains 

 of Mauritius, would connect by dry land. 



If, as I am informed, the soundings between Mau- 

 ritius and Bourbon do not exceed one hundred fathomSj^ 

 a rise of little more than six hundred feet would join 

 the two islands by dry lanfl. These islands being all 

 of them^ of volcanic origin ; Bourbon having still 

 an active volcano, while Mauritius shews evidence 

 of one or more craters of extinct volcanoes, such alter- 

 nations of rise and fall in the land, of which I have 

 given evidence on a small scale, can excite no surprize j 

 as volcanic islands have repeatedly risen and again 

 disappeared after a very short interval. 



But if v.e carry on our enquiries on a larger scale, 

 and examine the strata of the existing continents Ave 

 (liscover that all, except perhaps the highest mountain- 

 tops, have formed at some period the bed of the sea, and 

 the most celebrated of our paloentologists has expressed 

 the opinion tl^at every part of these continents — "has, 

 been oji the average, thirty times submerged and has 

 formed part of the sea bed during two-thirds of all the 

 past geological time ;" while on the other hand it may 

 be inferred that the present sea -bed has been dry land 

 as many different times, and it is therefore probable, 

 that Mauritius and its surrounding islands are the re- 

 maining mountain-tops of a submerged continent. 



The Flora of Mauritius, small as the island i8, con- 

 firms, to a considerable extent, this opinion. Together 

 with that of Bourboii it differs to a very great extent 

 from that of the luain-lands nearest to it in all direc- 

 tions ; it ixiay in short be said to have a peculiar Flora of 

 its own in Avhich only only l^Tth to l/8th of the 

 species are common to other lands. For so small a 

 tract of land it is extremely rich in species ; which, ex- 

 clusive of introduced or naturalized flowering plants 

 amount to nparly eight hundred ; while of these so far 

 as Ave af ))rcscnt knoAv, only 12a arc common to it and 

 India ; 101 to it and Madagascar ; 20 to America ; 16 to 

 Ceylon and 7 to the Cape cf Good Hope. Tlie pecu- 

 liarity of tlie Flora is as great as that of Australia or 

 \^S Cape of Cidod Uopr and indicates a centre offlorn^ 



