124 TENUIROSTKES. 



may be noticed on the branches, nlong the nnder 

 surface of whicli they are able to run with perfect 

 facility, in search of the insects that lie concealed in 

 holes and crevices of the bark. 



The type of this sub-family, — 



The Common Creeper (Gerthia familiaris), is a most 

 active and restless little bird, ever on the alert, and 

 climbing about the trunks and branches of trees, intent 

 on picking up its insect food. Though comparatively 

 common, and a constant resident in Britain, it is not 

 easily seen, for its celerity in shifting its position makes 

 it very difficult to follow it with the eye. At one mstant 

 it is before the spectator, and the next is hidden from 

 his view by the intervening trunk or branch, to the oppo- 

 site side of which it has passed in a moment. The form 

 of the tail, and structure of the feet, are beautifully 

 ada])ted for this sort of rapid locomotion. 



