450 



EXTINCTION OF SPECIES. 



[Ch. XLII. 



/ 



- — As an example 



of tlie rapidity with whicli a large tract may become 

 peopled by the offspring of a single pair of qnadrupeds, it may 



m 



from Norway 



mountains of Gnldbring 



Syssel, where they multiplied so greatly, in the course of forty 



meet 



from 



The rein-deer, observes a modern writer^ is in Lapland a 



man 



creature's paradise. There is, in the interior, a tract which 



Macken 



miles 



a sing-le human habitation, and almost en- 

 tirely unlmown to the natives themselves. There are no 

 wolves ; the Icelanders will keep out the bears ; and the rein- 



man 



whatever, unless it has brought with it its own tormentmg 



gad-fly* 



UUoa in his voyage, and Buffon on the authority of old 



writers, relate a fact which illustrates very clearly the prin- 

 ciple before explained, of the check which the increase of one 



necessarily offers to that of another. The Spaniards 

 had introduced goats into the island of Juan Fernandez, where 

 they became so prolific as to furnish the pirates who infested 

 those seas with provisions. In order to cut off this resource 

 from the buccaneers, a number of dogs were turned loose into 



animal 



numerous 



that they destroyed the goats in every accessible part, after 

 which the number of the wild dogs again decreased.f 



It is usually the first appearance of an animal or plant, in 

 a reo'ion to which it was previously a stranger, that gives rise 



to the chief alteration ; since, after a 



But it must require ages before such a 



time 



asain established. 



new adjustment of the relative forces of so many connicxmg 

 agents can be definitely settled. The causes in simultaneous 

 action are so numerous, that they admit of an almost infinite 



L 



^ Travels in Iceland in 1810, p. 342. 



t Bnffon, vol.T.-p.' 100. Ulloa's Voyage, vol. ii. p. 220. 





