38 Scientific Sophisms. 



cant a part in the great scheme of nature, one 

 is apt to wonder why a distinct species should 

 have been created ; but it should always be 

 recollected that in some other country perhaps 

 it is an essential member of society, or at some 

 former period may have been so." l And again : 

 In his description of the Passage of Cordillera, 

 he says, " I was very much struck with the 

 marked difference between the vegetation of 

 these eastern valleys and that of the opposite 

 side : yet the climate, as well as the kind of 

 soil, is nearly identical, and the difference of 

 longitude very trifling. The same remark holds 

 good with the quadrupeds, and in a lesser degree 

 with the birds and insects." "This fact," he 

 adds, "is in perfect accordance with the geo- 

 logical history of the Andes ; for these moun- 

 tains have existed as a great barrier since a 

 period so remote that whole races of animals 

 must subsequently have perished from the 

 face of the earth. Therefore, unless we sup- 

 pose the same species to have been created 

 in two different countries, we ought not to 

 expect any closer similarity between the organic 

 beings on opposite sides of the Andes, than 



1 " Narrative of the Surveying Voyages of H.M.'s Ships 

 Adventure and Beagle" London, 1839. Vol. iii. 



