SEXUAL SELECTION 467 



seen.* On the whole, birds appear to "be the most sesthetio 

 of all animals, excepting of course man, and they have 

 nearly the same taste for the beautiful as we hare. This 

 is shown by our enjoyment of the singing of birds, and by 

 our women, both civilized and savage, decking their heads 

 with borrowed plumes, and using gems which are hardly 

 more brilliantly colored than the naked skin and wattles 

 of certain birds. In man, however, when cultivated, the 

 sense of beauty is manifestly a far more complex feeling, 

 and is associated with various intellectual ideas. 



Before treating of the sexual characters with which we 

 are here more particularly concerned, I may just allude 

 to certain differences between the sexes which apparently 

 depend on differences in their habits of life; for such cases, 

 though common in the lower, are rare in the higher, classes. 

 Two hummingbirds belonging to the genus Eustephanus, 

 which inhabit the island of Juan Fernandez, were long 

 thought to be specifically distinct, but are now known, 

 as Mr. Gould informs me, to be the male and female of 

 the same species, and they differ slightly in the form of the 

 beak. In another genus of humming-birds {Orypus), the 

 beak of the male is serrated along the margin and hooked 

 at the extremity, thus differing much from that of the 

 female. In the Neomorpha of New Zealand, there is, as 

 we have seen, a still wider difference in the form of the 

 beak in relation to the manner of feeding of the two sexes. 

 Something of the same kind has been observed with the 

 goldfinch (^Carduelis elegana), for I am assured by Mr. J. 

 Jenner Weir that the bird-catchers can distinguish the males 

 by their slightly longer beaks. The flocks of males are 

 often found feeding on the seeds of the teazle (Dipsacus), 

 which they can reach with their elongated beaks, while 

 the females more commonly feed on the seeds of the betony 

 or Scrophularia. With a slight difference of this kind as 

 a foundation, we can see how the beaks of the two sexes 



« Gould, "Handbook to the Birds of Australia," 1866, vol. ii. p. 388. 



