PECULIAK COLORATION OF FLO WEES. 217 



of flowers of lofty elevations is the more intense actinic 

 properties of the unstrained light ; for, at the altitude of 

 a little over three miles, the rays have passed through only 

 one-half the quantity of air that those must traverse which 

 are unobstructed by mountain elevations before reaching 

 the ocean level. This peculiar coloration of flowers — the 

 predominance of blue and yellow — has been observed by 

 Bowles among the Rocky Mountains, at an elevation 

 exceeding only by a little one-half that at which the 

 phenomenon is most distinctly marked upon the Andes. 

 This would seem to indicate a less absorptive power 

 of the lower strata of the atmosphere of the temperate 

 zones, as compared with that of the tropics. The pale 

 shade, and often delicate white, of our eai*ly spring flow- 

 ers, and the richer and moi-e gaudy hues of summer and 

 autumn, are doubtless the result of the varied chemical 

 properties of the light during different portions of the 

 year. We observe tliat the humming-birds which flit so 

 constantly in the unstrained light of the lofty regions of 

 the Andes are more brilliantly colored than those found 

 upon the lowlands. May this also not be referred to the 

 same causes that effect the coloration of plants ? That 

 other birds of high flight are sometimes of a dull color, 

 may be explained, perhaj^s, by the counteracting influ- 

 ences of peculiar habits of life. 



From the paramo of Chimborazo the traveller looks 

 down upon the plateau of Quito, which, at this point, is 

 about twenty miles in -oidth. To the right lies the re- 

 nowned city of Riobamba, in the midst of an apparently 

 well-cultivated plain. A dreary ride over a dreary moor- 

 land, gradually descending, and we turned into the court- 

 yard of the tambo of Chuquipoys. The prospects afforded 

 by the miserable mud hovel were cheerless; but it was 

 at least a comforting reflection that the bleak pass was 

 crossed, and we were over the "Western Cordillera, al- 

 io 



