238 TKAXSACTIOXS AND PROCEEDINGS OF THE [Sess. L%nu. 



Bourbon. The principal island of the group, to which the 

 name Mauritius is applied, is a mountainous oceanic island 

 of volcanic origin, but no active volcano has been known 

 within the memory of man. The geological formation 

 consists of vesicular basalt, which, on decomposing, forms a 

 very porous red earth. 



The island has an area of 713 square miles, its greatest 

 length from north to south being 38 miles, and its breadth 

 from east to west 28 miles. 



The northern part of the island is a low plain, and the 

 centre consists of an elevated plateau surrounded by three 

 ranges of rugged mountains, reaching a height of 2711 feet 

 above sea-level in the Black Eiver Mountain, 



There are numerous streams of water, the largest of 

 which is twelve miles long. The lakes are few in number 

 and small in size. 



AMien Mauritius was discovered by the Portuguese in 

 1505, the island was clothed to the water's edge with 

 virgin forest, in which existed a large number of endemic 

 species of plants. On account of the terrific hurricanes 

 which occasionally visit the island, the trees were nowhere 

 high, but they formed a dense mass of nearly uniform 

 height, and they were thus better fitted to withstand the 

 violence of the wind. Beneath this dense canopy of ever- 

 green foliage, large numbers of shade and moisture-lo%dng 

 plants, such as orchids, ferns, club-mosses, and other 

 Cryptogams, found a genial home. During the present 

 century the greater part of the virgin forest has been 

 cleared away to make room for sugar-cane plantations, in 

 consequence of which many of the native plants have been 

 exterminated. Foreign plants have found their way into 

 the island, where they flourish, and have killed out many 

 of the native species. Thus, in Baker's " Flora of Mauritius 

 and the Seychelles," published in 1877, the number of 

 native flowering plants is only 705 species, whereas the 

 naturalised species number 269. 



Mauritius, being situated within three degrees of the 

 Tropic of Capricorn, has a tropical climate ; but owing to 

 its isolated position in the Indian Ocean and the cool 

 south-east trade wind which blows during the greater part 

 of the year, the climate is more temperate than that of 



