Transit- Expedition Naturalitsts at Rodriguez. 3G7 



1 have ])aicl specijil atteution to the Palms and Panduni. Of 

 the former there are three species indigenous — one of the genus 

 Lutitnia, and two belonging to the genus Areca. The Paadatd 

 present mueh greater dilKculty in their determination ; and I do 

 not yet feel in a position to fix deKnitely thr number of species, 

 although 1 rather incline to the idea that there are only two true 

 species. My collection of the plants of the island now lunnbers 

 about 450 species, of which about three fourths are Pha^nogams. 

 T have made observations with the view of discriminating between 

 the indigenous and introduced vegetation, but there are several 

 plants regarding which I am doubtful. I have not yet succeeded 

 in finding any marine Phajnogams ; hitherto, however, I have not 

 devoted much time to the marine flora. There are no tree ferns 

 on the island ; at least I have seen none, and, as far as I can 

 learn, none of the inhabitants have seen any. Ferns are repre- 

 sented by about two d(jzen species ; mosses and fresh\\ ater alga? 

 are not abundant, but lichens are very numerous, both as species 

 and as individuals. This flora is by no means so extensive as I 

 had expected ; but the survey of the island just concluded by the 

 officers of the ' Shearwater ' shows the island is only about half the 

 size it was previously supposed to be, it being only 11 miles long 

 by 4 miles broad. The island is a volcanic one, consisting of a 

 succession of lava-flo\^"s, radiating from one or more foci in the 

 centre of the island, and now worn away so as to form a series of 

 more or less parallel ridges, separated by deep ra\'ines. These 

 lava-flows are composed chiefly of a dark compact basalt, not un- 

 frequently becoming porph\Titic, and commonly exhibiting a marked 

 columnar structure ; and 1 have counted as many as twelve such 

 flows, lying one above the other, separated severally, either by beds 

 of conglomerate, or by beds of laterite, or variously coloured clayey 

 beds. Granite and sandstone do not occur in the island. At the 

 east and at the west ends of the island occur the only non-volcanic 

 rock in the island, namely coralline limestone, extending in huge 

 sheets over many acres of laud, and also occurring in detached 

 patches on the top of the basalt, often nearly a mile from the 

 sea. On the northern and southern sides of the island it does 

 not occur ; but on the southern side may be seen some raised 

 beaches, marking upheaval there, as does the coralline limestone 

 at the east and west sides. Zeolites are common in the basalt 

 in many places, as also several other minerals. The whole rocks 

 of the island are permeated by iron. This report is very brief ; 

 but I have abstained from entering into details regarding the 

 botany and geology of the island, leaving that for the full report 

 to be given in on my return. I trust, however, the above is suffi- 

 cient to show that I have made some progress towards accomplishing 

 the objects for which I was sent out here. 



I am. Sir, 

 To the Secretary of Tours faithfidly, 



the Royal Society. Is. Batlet Balfouh. 



