DISTRIBUTION IN SPACE 133 



retire Equator-wards to winter. The great head- 

 quarters of the Trochilidae are in the northern 

 portions of the Neotropical Region, especially 

 in Ecuador, in the mountainous areas of the 

 Andes for about ten degrees north and south 

 of the Equator. The lowlands are comparatively 

 poor in species, and present the least metallic 

 colouring. The Humming-Birds decrease in 

 numbers farther south as we approach Chile 

 and the Argentine, although the family is re- 

 presented even as low as Cape Horn itself ; 

 whilst northwards, wdth the exception of the 

 West Indies and Central America, where these 

 birds are certainly plentiful, w^e find a rapid 

 falling off in numbers, and but a single species 

 penetrates as far as Alaska. 



Our fifth sub-order is a remarkably small one, 

 the Colli, composed of a single family, the Colies 

 (Coliidae). These peculiar little birds, bearing a 

 superficial resemblance to a small Finch, with a 

 very long tail and a conspicuous crest, are con- 

 fined to the Ethiopian Region, but do not extend 

 to Madagascar. There are some eight or nine 

 species only. The sixth sub-order, the Trogones, 

 is also a small one, and composed of a single 

 family. The Trogons are a group of curious 

 and bright-coloured birds confined to the 



