2 TRAVELS AMONGST THE GREAT ANDES. 



so large a portion must be left out of the examination. The few 

 remarks I have to make must further be restricted almost exclusively 

 to the Coleojitera. There is the less disadvantage in this that the 

 collections made by Mr. Whymper at very high altitudes consisted 

 largely of this order of Insects, and that Coleoptera, by their great 

 number and ubiquity, and the tendency to definiteness in their areas of 

 distribution, offer better material for this class of inquiry than almost 

 any other group of organisms. 



The remarkable relationship which exists between the Fauna and 

 Flora of Chili and those of high latitudes in North America, and even 

 Europe, has often been discussed by writers on Geographical Distribu- 

 tion. In Darwin's Origin of S;pecies it is stated (on the authority of Sir 

 Joseph Hooker) that not fewer than 46 species of flowering plants of 

 Chili and Europe are identical, — North America showing evidence of its 

 having lain in the path of the supposed migration. The number of 

 flowering plants common to these regions and the remarkable general 

 similarity in their Botanical products has been, quite recently, shown by 

 Dr. Philippi, the Chilian Botanist, to be much greater even than stated 

 by Darwin. An analogous relationship has also been pointed out in 

 their animal forms. In Insects, for example, numerous genera are com- 

 mon to the three regions, which are totally absent from the intervening 

 Tropical and warm Temperate zones of America. The curious and 

 puzzling feature in these classes of facts is that, as far as Insects and 

 Plants are concerned, the relationship is not of the same degree. In 

 Plants there is a large amount of identity as to species, but in Insects 

 there is little or none ; the relationship is generic only. The explana- 

 tion of the proportional identity of Plants offered by Darwin — namely, 

 that the species migrated along the high lands of the Andes from north 

 to south during the Glacial epoch, does not meet the case of the more 

 distant relationship of the respective Insect Faunas. Darwin's explana- 

 tion had been previously applied to account for similar relationship 

 between the Faunas of south and north temperate latitudes in the old 

 world, and has been almost universally adopted. With good reason, 

 for here we have the remarkable evidence of its validity offered l)y the 



