Ch, XLI.] 



EEFEEENCE TO THE OEIGIN OF SPECIES. 



431 



sometimes 



sj 



^ 



i 



M 



I 



1^ 



w 



\ 



up into tlie air by the aqueous vapour. The eggs of a pupa 



minute 



from Ma 



slight that they might be carried many miles b; 



before alighting on the ground — as far perhaps as 



deira to the Dezertas. There is no reason for supposing 



that the tendency of species to form new varieties is greater 



in an oceanic island than on a continent. But if islands be 



s 



separated from each other throughout so long a period a 

 would be sufficient on the continent to change most of the 

 species^ then it is evident that there will be a greater manu- 

 facture of new species in the islands. Let us suppose a band 

 of emigrants to have gone from some European country a 

 thousand years ago and to have formed colonies in the Azores^ 

 Canaries, and Madeiras, and that all communication between 

 them and the mother country and between the different 

 archipelagos was cut off for a thousand years, there would then 

 be in all probability four languages spoken between the 

 mother country and her three colonies all different from the 

 original tongue of the ninth century. The population of 

 the three archipelagos, like the area of land formed by the 



whole 



migrht be verv insignificant com 



emigr 



pro- 



that of the country from which the first 

 ceededj yet the smaller number of islanders, in consequence of 

 their isolation, would have given rise to three new languages, 

 and the inhabitants of the continent to one only. Not that 

 the invention of new terms and idioms or the disuse of old 

 ones would have gone on at a greater rate in the islands^ 

 but because each archipelago being separated from every other 

 one and from the rest of the world, had formed an independent 

 linguistic centre. In like manner the distinctness of the 

 landshells in the Canaries, Madeiras, and Azores, and in 

 many of the separate islands of each, are the results of the 

 prolonged isolation of small fragments of land in mid-ocean, 



not of a greater tendency in the testacea inhabiting such 

 islands to vary. 



In conclusion I may observe, that the extent to which the 

 species of mammalia, birds, insects, landshells, and plants, 

 (whether flowering or cryptogamous,) agree with continental 



