152 INTRODUCTION. 



and perfecting one of the most important properties 

 of vegetation. * 



The Nectar inladce, or Sun-birds, are placed by 

 Mr. Swainson as the sub-typical family of the Te- 

 nuirostres or suctorial and slender-billed birds, of 

 which the True Humming-birds stand as the most 

 developed form. The five genera which the same 

 gentleman has taken to represent the principle mo- 

 difications of structure (1. Melithreptus, 2. Necta- 

 rinia, 3. Anthreptes, 4. Ccereba, 5. Diceimi) near- 

 ly show also their geographic distribution. The 

 second or typical form is confined nearly to the 

 tropics of the Old World, there holding the same 

 rank in distribution as the more perfect Trochilida?. 

 The first is confined to the islands of the Pacific 

 Ocean, exhibiting a variety of the form there ; while 

 the fourth, extremely limited in species, another 

 family entirely almost occupying its place, is proper 

 to America only, extending a very short way be- 

 yond the boundary of the southern continent. The 

 third, which shows only a stronger developed varia- 

 tion of Nectarinia, is chiefly found in continental 

 India, extending in small proportion to Africa; 

 while the fifth is intermediate between the third 

 and fourth, both in form and in locality, the Aus- 

 tralian islands being its more peculiar strong-hold. 



In the colouring of the group we find also a kind 



* Vaillant- considers the Humming-birds and Sun-birds re- 

 present, in their own class, the Bees and Butterflies among 

 insects, performing, like them, the same services of impregna- 

 tion. 



