CHANGES IN THE VEGETATION. 289 



species, occur embedded in the soil. It proves to 

 be a Cochlogena, or land-shell of a very peculiar 

 form ;* with it I found six other kinds ; and in 

 another spot an eighth species. It is remarkable 

 that none of them are now found living. Their 

 extinction has probably been caused by the entire 

 destruction of the woods, and the consequent loss 

 of food and shelter, which occurred during the 

 early part of the last century. 



The history of the changes which the elevated 

 plains of Longwood and Deadwood have imder- 

 gone, as given in General Beatson's account of the 

 island, is extremely curious. Both plains, it is 

 said, in former times were covered with wood, and 

 were therefore called the Great Wood. So late 

 as the year 1716 there were many trees, but in 

 1724 the old trees had mostly fallen ; and as goats 

 and hogs had been suffered to range about, all the 

 young trees had been killed. It appeal's also from 

 the official records that the trees were unexpect- 

 edly, some years afterwards, succeeded by a wire 

 grass, which spread over the whole surface.! Gen- 

 eral Beatson adds, that now this plain " is covered 

 with fine sward, and is become the finest piece of 

 pasture on the island." The extent of surface, 

 probably covered by wood at a former period, is 

 estimated at no less than two thousand acres ; at 

 the present day scarcely a single tree can be found 

 there. It is also said that in 1709 there were 

 quantities of dead trees in Sandy Bay ; this place 

 is now so utterly desert, that nothing but so well 

 attested an account could have made me believe 

 that they could ever have gTO\vn there. The fact 

 that the goats and hogs destroyed all the young 



* It deserves notice, tliat all the many specimens of this shell 

 found by me in one spot differ, as a marked variety, from another 

 set of specimens procured from a different spot. 



t Beatson's St. Helena. Introductory chapter, p. 4. 

 II. 19 



