CHAP. XIV.] 
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 Equidae 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. 
