BIRDS. 441 



these birds are ornamented. Almost every part of their 

 plumage has been taken advantage of and modified; and 

 the modifications have been carried, as Mr. Gould showed 

 me, to a wonderful extreme in some species belonging tc 

 nearly every sub-group. Such cases are curiously like 

 those which we see in our fancy breeds, reared by man for 

 the sake of ornament; certain individuals originally varied 

 in one character, and other individuals of the same species 

 in other characters; and these have been seized on by man 

 and much augmented, as shown by the tail of the fantail- 

 pigeon, the hood of the jacobin, the beak and wattle of 

 the carrier, and so forth. The sole difference between these 

 cases is that in the one the result is due to man's selection, 

 while in the other, as with humming-birds, birds of para- 

 dise, etc., it is due to the selection by the females of the 

 more beautiful males. 



I will mention only one other bird, remarkable from the 

 extreme contrast in color between the sexes, namely, the 

 famous bell-bird (Chasmorhynchus niveus) of South 

 America, the note of which can be distinguished at the 

 distance of nearly three miles, and astonishes every one 

 when first hearing it. The male is pure white, while the 

 female is dusky-green; and white is a very rare color in ter- 

 restrial species of moderate size and inoffensive habits. 

 The male, also, as described by Waterton, has a spiral tube 

 nearly three inches in length, which rises from the base of 

 the beak. It is jet-black, dotted over with minute downy 

 feathers. This tube can be inflated with air, through a 

 communication with the palate ; and when not inflated 

 hangs down on one side. The genus consists of four species, 

 the males of which are very distinct, while the females, as 

 described by Mr. Sclater in a very interesting paper, closely 

 resemble each other, thus offering an excellent instance of 

 the common rule that within the same group the males 

 differ much more from each other than do the females. In 

 a second species (0. nudicollis) the male is likewise snow- 

 white, with the exception of a large space of naked skin 

 on the throat and round the eyes, which during the breed- 

 ing-season is of a fine green color. In the third specif js 

 (C. tricarunculatus) the head and neck alone of the mule 

 are white, the rest of the body being chestnut-brown, and 

 the male of this species is provided with three filamentous 

 projections half as long as the body, one rising from the 



