XIII THE COLOURS OF BIRDS 275 



colours which are especially characteristic of hum- 

 ming-birds, however, occur, as is well known, in 

 patches of extraordinary brilliancy either on the 

 head as a crest, or on the lower surface, especially of 

 the throat. The feathers forming these patches are 

 peculiarly modified, and may display any of the 

 colours of the spectrum including ruby-red and 

 golden-yellow — the colours which are so markedly 

 absent from the metallic feathers of sun-birds. The 

 rectrices of humming-birds not infrequently display 

 metallic colour, which may be distributed over the 

 whole feather, or may be limited to a transverse band 

 near the tip. Longitudinal bands of metallic colour 

 like those of the sun-birds do not seem to occur. 



Pigmental colours among humming-birds are not 

 remarkable for brightness of tint, being usually shades 

 of gray or dull brown. The only marked exception 

 is the colour called by systematists " rich chestnut " 

 or " cinnamon," which is often limited to the males, 

 as, for example, in Eustephanus fernandensis. In 

 this connection it may be noticed that not only 

 are metallic tints almost invariably absent from the 

 wings, but where, as in the above species, the male 

 as compared with the female is characterised by the 

 development of a special pigmental colour, this pig- 

 ment is entirely absent from the wing-quills, though 

 present in the wing-coverts. 



As an exception to the general rule that the 

 humming-birds display great brilliancy, we find that 

 the so-called " hermit " forms which live in the deep 

 shades of the forests are only soberly tinted, with 

 little metallic colour ; of these the genus Phathornis 

 may be taken as a type. 



