HUMMING-BIRDS OF THE CORDILLERAS. 377 



varies in the species ; and the well-practised ear of the natu- 

 ralist is often able to distinguish without difficulty one from 

 the other. Some are furnished with strong wings, with 

 which they can extend their flight over a large extent of 

 country ; and many are migratory. Others again have only 

 small wings, and are compelled to remain always in the 

 same locality. So rapid is their flight, that the eye can 

 scarcely distinguish the little bird as it cleaves the air ; and 

 when hovering over a flower, the wings appear like filmy 

 gray fans on either side. 



The food of most species consists partly of insects and 

 partly of the honey extracted from flowers. In order to 

 obtain its food from the deep recesses of flowers, it possesses 

 a long delicate beak ; in some birds straight, in others curved 

 downwards, while some, again, have a double curve. These 

 variations in form are undoubtedly to suit the particular 

 flowers on which they feed. By means of the peculiar struc- 

 ture of its tongue, which is long, filamentous, and doubled 

 nearly to the base, it is enabled to project it to a great dis- 

 tance even into the very depths of the largest flowers. 



There are upwards of three hundred species of these beau- 

 tiful birds, and others are being constantly discovered one 

 vying with the other in beauty and richness of plumage truly 

 described as the " feathered gems of the mountain and forest." 

 Some humming-birds tower, like the lark, to a great height in 

 the air; while others keep always near the ground, among the 

 shrubs in which they live. 



The nests of humming-birds vary in form and structure, 

 but they are all of a most delicate nature. The external 

 parts of some are formed of light gray lichen, and so perfectly 

 arranged round it as to appear at a little distance as if only 



