THE HUMMING BIRDS. 263 



the nearest relatives they have in other countries. When, in the classi- 

 fication of birds, superficial or general resemblance was more considered 

 than structural affinity, the Humming Birds were supposed to have 

 representatives in the tropical regions of the eastern hemisphere in the 

 Sun Birds {Nectaruiiidw)', but the latter belong to a diftereut order, 

 Passeres, and are not very unlike, in their general structure, the Ameri- 

 can family of Honey Creepers {Cwrebidcv), of which they may be con- 

 sidered the more brilliantly colored Old World analogues. 



Of all the msmj families of birds which are entirely peculiar to the 

 rich bird-fauna of America, the Humming Birds probably constitute 

 the most numerous assemblage, about 500 distinct kinds being now 

 known, while others are being brought to light with almost every fresh 

 collection made in Mexico, Central America, or the higher lauds of 

 South America. 



They abound most in mountainous countries, where the configuration 

 of the surface and productions of the soil are most diversified within 

 small areas. Their center of abundance is among the northern Andes, 

 between the paralleFs of 10 degrees north and south of the equator, from 

 which region they gradually diminish in numbers both to the northward 

 and southward, but much more rapidly toward the extensive lowlands 

 of the eastern portion of the continent. The northern limit of their 

 abundance may be approximately given as the Tropic of Cancer, be- 

 yond which but few of the fifty Mexican species extend, while only 

 eighteen of them have been detected across the boundary line in the 

 equally mountainous portions of the southwestern United States, in- 

 cluding the semitropical Rio Grande Valley. Small as this number 

 may appear, the southwestern i^ortion of the Union may be considered 

 richly endowed compared with the vast valley of the Mississippi and 

 the Atlantic water-shed, a region of unsurpassed fertility and luxuriant 

 vegetation, yet which throughout its whole extent, even including the 

 peninsula of Florida, possesses only a single species of Humming Bird ! 

 In this scarcity, compared witli the western mountainous regions, of 

 representatives of a numerous family of birds, we see a certain paral- 

 lelism with the lowlands of eastern South America as compared with 

 the Andean highlands, only, on account of climatic differences, the con- 

 trast is by far more marked. A peculiar group of Humming Birds, 

 the Hermit Hummers (genera Phaethornis, Glaucis, Androdon, and 

 Rkamphodon), is more numerously represented in Brazil than elsewhere. 

 These iire all very plainly colored birds, with little metallic coloring, 

 sometimes none, and instead of living in the sunshine and feeding 

 among flowers they inhabit the gloomy forests and subsist wholly on 

 insects gleaned from the branches and leaves of trees. Apart from these, 

 however. Humming Birds are j^oorly represented in Brazil, compared 

 with the Andean highlaiuls. Mr. Gould comments on this as follows : 



Other boantiful kinds do here and there exist in Brazil, such as the Chrysolampis 

 moschitns [Ruby and Topaz], the Topaza pella [Topaz-throat], and the Lophornithes 

 [Cocxnotto Hnniming Birds] ; but tlio greater number are comparatively small and 



