CHAP. XIY.] 



ST. HELENA. 



297 



and they no more imply any closer connection between the 

 distant countries the allied forms now inhabit, than does the ex- 

 istence of living Equidse in South Africa and extinct Equidse in 

 the Pliocene deposits of the Pampas, imply a continent bridging 

 the South Atlantic to allow of their easy communication. 



Concluding Remarks on St. Helena. — The sketch we have now 

 given of the chief members of the indigenous fauna and flora of 

 St. Helena shows, that by means of the knowledge we have 

 obtained of past changes in the physical history of the earth, 

 and of the various modes by which organisms are conveyed 

 across the ocean, all the more important facts become readily 

 intelligible. We have here an island of small size and great 

 antiquity, very distant from every other land, and probably at no 

 time very much less distant from surrounding continents, which 

 became stocked by chance immigrants from other countries at 

 some remote epoch, and which has preserved many of their more 

 or less modified descendants to the present time. When first 

 visited by civilised man it was in all probability far more richly 

 stocked with plants and animals, forming a kind of natural 

 museum or vivarium in which ancient types, perhaps dating 

 back to the Miocene period, or even earlier, had been saved from 

 the destruction which has overtaken their allies on the great 

 continents. Unfortunately many, we do not know how many, 

 of these forms have been exterminated by the carelessness and 

 improvidence of its civilised but ignorant rulers; and it is only 

 by the extreme ruggedness and inaccessibility of its peaks and 

 crater-ridges that the scanty fragments have escaped by which 

 alone we are able to obtain a glimpse of this interesting chapter 

 in the life-history of our earth. 



