INTRODUCTION. 3 



products of high altitudes within the old world tropics, and those of low 

 lauds near the Arctic zone and the moiintains of temperate latitudes. 

 jNIultitudes of closely-allied or identical species are now found in these 

 various localities, thus indicating the paths that species took, Avhen 

 driven by the great climatic changes of the Glacial peri(jd. The ques- 

 tion then arises. Have we any similar proof of a glacial migration in 

 Tropical xVmerica ? 



Any final conclusion on this point, at any rate as regards the 

 Insects, has hitherto been deferred, on account of our ignorance of the 

 products of the high Andes at elevations near the snowdine. The 

 researches of Hundioldt and Bonpland in this direction were unsatis- 

 factory, as no species were obtained at great elevations ; and, like those 

 famous travellers, subsetpient explorers have brought away from the 

 upper slopes and vallej's of Ecuador and Coloml)ia, until within the last 

 few years, only Tropical American forms, or species of Andean genera 

 closely allied to the products of the plains at their feet. There was 

 no trace of the great host of genera and species characteristic of similar 

 local conditions in north and south temperate latitudes. The mountain- 

 living genera Carabus and Nchria of the old world temi^erate fauna and 

 of North America, or their Chilian allies Ceroglossus, Migadnps and very 

 many others, certainly ought to be found, if the inferences drawn from 

 the botanical relationship were as sound as they appear to be. Shortly 

 before Mr. Whymper's wonderful ascents of the snow-capped peaks of 

 Ecuador, a few Coleoptera and Lepidoptera from high elevations there 

 and in Coloml)ia had reached Europe, and went far to discourage any 

 expectations ; but we may sa\' that Mr. Whymper's more thorough 

 and complete search, at all elevations and on nearly all the loftier 

 mountains, has set the question at rest. If there had lieen any distinct 

 element of a North Temperate or >South Temperate Coleopterous Fauna 

 on the Ecuadorian Andes the collections he made, inexhaustivc though 

 they may be, would have shown some traces of it ; but there are none. 

 A few genera Ijelonging to temperate latitudes, though not found in 

 the tropical lowlands, do indeed occur, Ijut they are forms of almost 

 world-wide distriliution in similar climates, and there is no representa- 



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