Ch. VII.] TOXGUE OF HUMMING-BIRDS. 113 



have seen the Petasophora fly into the centre of a dancing 



column of midges and rapidly darting first at one and 



then at another secure half a dozen of the tiny flies 



before the column was broken up ; then retire to a 



branch and wait until it was re-formed, when it made 



another sudden descent on them. A fourth species 



(Heliothnx bar rot i, Bourc.), brilliant green above, white 



below, with a shining purple crest, has also a short bill, 



and I never saw it about flowers, but always hovering 



underneath leaves and searching for the small soft-bodied 



spiders that are found there. Two of them that I 



examined, both had these spiders in their crops. I have 



no doubt many humming-birds suck the honey from 



flowers, as I have seen it exude from their bills when 



shot ; but others do not frequent them ; and the principal 



food of all is small insects. I have examined scores 



of them, and never without finding insects in their crops. 



Their generally long bills have been spoken of by some 



naturalists as tubes into which they suck the honey by a 



piston-like movement of the tongue ; but suction in the 



usual way would be just as effective ; and I am satisfied 



that this is not the primary use of the tongue, nor of 



the- mechanism which enables it to be exserted to a 



great length beyond the end of the bill. The tongue, for 



one-half of its length, is semi-horny and cleft in two, 



Tongue of Humming-bird, with the blades a little opened. 



the two halves are laid flat against each other when at 

 rest, but can be separated at the will of the bird and 

 form a delicate pliable pair of forceps, most admirably 



