160 EVOLUTION AND DOGMA. 



Even in the case of the vegetable organisms 

 which Mr. Carruthers puts in evidence, there is 

 reason to believe that the variations in climate to 

 which they have been subject, have been far less 

 than is usually thought. We can say of these what 

 Darwin asserts of certain Arctic forms, that " they 

 will not have been exposed to any great diversity of 

 temperature and, as they all migrated in a body 

 together, their mutual relations will not have been 

 much disturbed." ' Where, however, Arctic species 

 have been left stranded on Alpine areas by the 

 retreat of glaciation, and where the species thus 

 isolated have been subsequently exposed to differ- 

 ences of climate, and to the influences of foreign 

 plants and insects, we would expect to discover 

 evidences of transmutation, to find the stranded 

 species to differ, not only from their parent Arctic 

 forms, but to differ also from those of the same 

 origin occurring on neighboring mountain ranges. 

 And this is what Darwin tells us is the fact, " for if," 

 he says, " we compare the present Alpine plants and 

 animals of the several great European mountain 

 ranges, one with another, though many of the 

 species remain identically the same, some exist as 

 varieties, some as doubtful forms or sub-species, and 

 some as distinct, yet closely allied species, repre- 

 senting each other on the several ranges." '' 



In the instance just quoted, as in countless 

 others that might be adduced, we have an illustra- 

 tion of a phenomenon with which all naturalists are 



1 " The Origin of Species," vol. II, p. 154. 

 2 Op. cit. vol. II, p. 155. 



