GE0GEAP1IY AND BOTANY OE THE ISLANDS. 
17* 
Rodriguez is situated east, and a little north of Mauritius, at a 
distance from it of 300 miles, in between 19° and 20° south latitude. 
It measures eleven miles in length by five miles in breadth, and the 
hills of the interior reach a little over 1000 feet above sea-level* 
The climate is completely similar to that of Mauritius, and the sub- 
jacent rock is entirely volcanic. The general character presented by 
the surface of the island is a dry parched volcanic soil, with many 
deeply-excavated stream-courses, now for the most part dried up. The 
highest ground and deepest ravines are on the east, and their slopes 
are covered with a thick scrub, mixed with ferns and weeds, and scat- 
tered over them are a considerable number of shrubs and trees, 
especially Pandani. On the west side the altitude is lower, the ravines 
are not so deep, and the ground slopes gradually towards the south. 
The land is covered with stones, and nearly destitute of trees and 
shrubs, and the ground over wide areas is covered with a scant coating 
of grasses and Cyperacece , mixed with social weeds. At the south-west 
end of the island is a low plain of coralline limestone, which yields 
several of the endemic species, as Nesogenes , Abrotanella , and the two 
species of Hypoestes. Here, as in Mauritius, our earliest records of the 
island, which go back to 1691, report it as richly wooded. Now the 
forests have been all cut down, and flocks of goats and herds of cattle 
graze over its surface and nip the young shoots of everything they can 
reach. Through Dr. Balfour’s explorations we now know in the island 
202 wild species of Flowering Plants and Ferns. Of these, 36 are peculiar 
to the island, and three represent monotypic endemic genera, Mcithu- 
rinia , ScypJiochlamys, and Tanulepis. Notably the proportions of 
Ferns and Orchids is smaller than in Mauritius. 
The following table shows the number of species in each systematic 
subdivision which our flora includes. In looking at this table, it must 
be borne in mind that all numerical statements which have been hitherto 
made in regard to the flora of Mauritius have rested upon the data of 
Bojer, and that by using the standard of what constitutes a species 
which has been employed in the Kew colonial floras, Bojer’s figures are 
materially reduced. For instance, in the ‘ Hortus Mauritianus ’ the 
vascular Cryptogams of the island are counted at 218, whilst our 
estimate of their number is 164, and it is probable that a reduction of 
25 per cent, will represent a fair average of the difference between the 
two standards : — 
b 
