HUMMING-BIRDS. 21 



fly oflT together. Their food generally consists of fruit and berries, occasionally 

 insects being taken, when their other sustenance is scanty. 



At the Cape the white-backed coly (C. caipensis) is not uncommon in gardens 

 during the fruit-season, ranging about in small families of from six to eight 

 individuals. They fly with a rapid, though laboured flight, generally at a lower 

 level than the object at which they aim, and on nearing it they rise upward with 

 a sudden abrupt curve. They creep about the branches like parrots, and hang, 

 head downwards, without inconvenience ; indeed, it is said that they invariably 

 sleep in this position, many of them congregated together in a ball. In Natal 

 Mr. Ayres states that the white-backed coly lives entirely on fruits, as does Mr. 

 Andersson, who gives some information as to the flight and nesting-habits of the 

 species. The flight, he says, is short and feeble, seldom extending beyond the 

 nearest bush or tree, on reaching which the bird perches on one of the lower 

 branches, and then gradually glides and. creeps upwards through the foliage, 

 using both bill and feet for that purpose. The nest he found in a small bush ; it 

 was composed externally of grass and twigs, lined internally with soft grass ; the 

 eggs were white, and three in number. Another well-known representative of 

 the genus is the South African coly ((7. striatus), which is brown above with 

 numerous dusky cross-lines on the plumage, the head being crested and a little 

 more ashy, while the forehead and lores are reddish, the sides of the face, throat, 

 and breast ashy brown, the latter with blackish cross-lines ; the rest of the under 

 surface being .ochrey bufl! The total length of the typical form is about 14 inches ; 

 but there is considerable local variation in this respect. Large at the Cape, the 

 bird becomes smaller as it approaches Abyssinia, but is of about the same size 

 in Senegambia^ and then gradually decreases in size in its west coast habitats ; 

 this variation in size being an invariable rule with African birds. The South 

 African coly breeds in Natal, building its nest in the thick fork of a mimosa or 

 other low tree, well sheltered by creepers and foliage above. 



The Humming-Birds. 



Family TbochiliDuE. 



Mainly confined to Central and South America, where they range from the 

 steaming tropical forests of Brazil to the cold and barren rocks of Tierra del Fuego, 

 but ^(Iso extending into Mexico, humming-birds are now regarded, in spite of their 

 difference in form and habits, as near allies of t^ie swifts. To a certain extent, 

 indeed, the difference in the two groups is not so strongly marked in the young as 

 in the adult condition, seeing that, while in the full-grown humming-bird the beak 

 is always long and slender, in the nestling it is short and wide like that of a swift. 

 In the structure of their palate, according to recent researches, both groups conform 

 to the Passerine type. Having the keel of the breast-bone well developed, in 

 accordance with their marvellous power of sustained' flight, the humming-birds are 

 •characterised by the presence of ten feathers in the tail, and the same number of 

 primary quills in the wing ; while the secondaries are reduced to six, and are thus 

 very different to those of the perching birds. The three forwardly-directed toes are 



