IV. 



HUMMING-BIEDS : 



AS ILLUSTRATING THE LUXUPJANCE OF TROPICAL 

 NATURE. 



Structure— Colours and Ornaments — Display of Ornaments by the Male — 

 Descriptive Names — The Motions and Habits of Humming-birds — Food 

 • — Nests — Geographical Distribution and Variation — Humming-birds of 

 Juan Fernandez as illustrating Variation and Natural Selection — The 

 relations and affinities of Humming-birds — How to determine doubtful 

 affinities — Resemblances of Swifts and Humming-birds — Differences 

 between Sun-birds and Humming-birds — Conclusion. 



There are now about ten thousand different kinds of 

 birds known to naturalists, and these are classed in one 

 hundred and thirty families which vary greatly in extent, 

 some containing a single species only, while others 

 comprise many hundreds. The two largest families 

 are those of the warblers, with more than six hundred, 

 and the finches with more than five hundred species, 

 spread over the whole globe ; the hawks and the pigeons, 

 also spread over the whole globe, number about three 

 hundred and thirty, and three hundred and sixty species 

 respectively ; while the diminutive humming-birds, 

 confined to one hemisphere, consist of about four 

 hundred different species. They are thus, as regards 

 the number of distinct kinds collected in a limited area, 



