402 PERCY SLADEN TRUST EXPEDITION 



the Aldabra flora would be very poor even for a coral island, but this is not the case, for it 

 is covered with a type of vegetation which appears to dispense easily with soil, provided 

 there are crannies and fissures in the rock, into which roots can be driven : this vegetation 

 takes the form of a low jungle or bush 10—20 feet high, which densely clothes every foot 

 of rock. 



The average height of the land above high tide-mark is about 12 feet, though an 

 elevation of 1 5 feet is usually found near the seashore, from which point there is a gradual 

 slope down to the lagoon. 



Seaward the land is bounded by rocky cliffs (15 feet high), which are always much 

 overhanging, obviously being washed away by the sea. Large fallen masses of rock are 

 frequent, lying on the reef below, and at intervals caverns pass up into the cliff-face, often 

 to find openings to the surface some distance inland. Where the cliffs have been washed 

 away unevenly, small protected bays are formed and these get partly choked with sand 

 and then form small sand-beaches known locally as " lances," the only landing-places for 

 boats and favourite breeding-grounds of the green turtle (Chelone mydas). Within a 

 short distance of the top of the cliffs the bush begins. To explore the country tracks 

 about 6 feet wide were cut across the land-rim through the bush from the sea-cliffs to the 

 lagoon and then by means of smaller paths the land surface on each side was examined. 

 This somewhat laborious method was chosen on account of the extreme density of the 

 vegetation, which is so impenetrable that it is quite impossible to proceed in any direction 

 without employing several men to cut a path ; in addition these " sections," as I shall in 

 future term them, proved of great interest as showing the complete dependence of each 

 class of vegetation on the type of rock which supports it. 



In order to demonstrate more clearly the types of country encountered, two of 

 these sections may be described, one typical of the north of the atoll and the other of 

 the south. 



The typical sectional track across the land-rim in the north of the atoll. This section 

 passes across Malabar Island, about 3 miles from Passe Houareau, and is opposite an 

 island in the lagoon known as Verte. From the sea cliffs the rock at first is moderately 

 rough and strikes the observer forcibly from the fact that it is composed of corals which, 

 though fossil, are but little broken and are undoubtedly in the same relative positions as 

 when alive. This type of rock is always found in the sea cliffs and for some little distance 

 inland. It is usually sparsely covered with sand blown up from the reefs forming a little 

 soil which supports the type of vegetation usually found on coral sand islands ; bushes of 

 SccBvola* and Tournefortiaf are common and at intervals large clumps of screw-pines { 

 occur. On the northern part of the land-rim this country is only a few yards wide, and 

 then both rock and vegetation rapidly change ; the edge of a dense jungle rises like a wall 

 and thenceforward no natural paths or glades occur and every inch has to be gained at 

 the expense of much time and labour. The rock becomes more rough until its surface 

 resembles a miniature forest of little pinnacles and sharp jagged edges, which make 

 progression difficult. The jungle is composed largely of Pemphis acidula, a tree known 

 locally as " almond-tree " ; it has a very hard wood and grows so thickly that the bush is 



* Sccevola kosniyii. t Tournefortia argentea. \ Pandanus vandermeeschii. 



