ON THE SAND-REEF ANB MOUNTAIN. 233 



have no congeners in the forest on the mourie or 

 savannah they originated, and there they remain, 

 every generation becoming more and more fitted 

 to their habitat. The most striking examples 

 here, as everywhere else are the orchids. We have 

 already mentioned the Crytopodiums, but the 

 Sobralias show even more adaptability to circum- 

 stances. So distinct are they, that a novice would 

 put them down at once as dwarf bamboos rather 

 than orchids. Instead of pseudo-bulbs, fleshy 

 stems and delicate leaves, they have wiry stalks 

 and dry hairy foliage, only the magnificent 

 blossoms indicating at once their family. These 

 have obviously been developed on the sand-reef 

 or mountain, probably from something like the 

 Cleistes rosea of the pipe-clay savannah. Another 

 genus which must also have arisen in the same 

 localities is the Vanilla, the only true climber in 

 the order. Here we have an elongated fleshy 

 stem either growing in the sand or entirely 

 detached, and therefore an epiphyte as much as 

 most of its cousins. By means of its power of 

 storing moisture in fleshy aerial roots, stems, and 

 leaves, it is able to endure the strongest sunlight 

 and thrive where the others would be quickly 

 shrivelled up. 



In the forest proper all the plants are perennial 



