344 



STERNA OF HUMMING BIRDS. 



feed on the sweet juice of blossoms, to acquire which 

 there must be much use of the wing before even a 

 little bird can procure a meal. Thus, though the 

 wings of these birds cannot be considered as the 

 most general or immediate of their organs in feeding, 

 they are very essential in some, and in all they are 

 auxiliaries which need to be constantly in readiness. 

 As the wings, even of those species which use them 

 the most in feeding, are not used for long stretches, 

 but merely for flitting about from flower to flower, 

 they all have the character of twitching wings, which 

 take the air by sudden jerks more than of wings 

 of forward flight ; but notwithstanding this undulating 

 style of flight, some of them get through the air with 

 much rapidity. We shall select as specimens for 

 illustrating the sternal apparatus of the tribe, one of 

 the humming-birds of the tropical parts of America, 

 which is a feeder on the wing, and the common 

 hoopoe, which is a summer migrant in the wanner 

 parts of Europe, and feeds on the ground or on trees. 



Humming Bird. 



The sternal apparatus of these very small birds is, 

 as may be seen by the figure, remarkably well deve- 

 loped, though, like that of the swallow tribe, it com- 

 bines not a little of the character of a carrying basket 



