WOODPECKERS. 203 



the chin, one on each side of the throat, go com- 

 pletely round the back of the head, and meeting 

 at a point on the forehead, are there inserted into 

 the skull. These branches being highly elastic, 

 free through their whole length, except at the very 

 extremity, and moved by proper muscles both of 

 extension and retraction, are capable of being 

 alternately lengthened and shortened, by which 

 motion the horny tip of the tongue is propelled 

 far beyond the point of the beak, and drawn in 

 again, with a rapidity almost greater than the eye 

 can follow. 



SKULL OF WOODPECKER. 



Add to this, that there is on each side of the 

 head a very large gland, which secretes a glutinous 

 substance ; this gland being embraced and com- 

 pressed by the action of the muscle that protrudes 

 the tongue, the viscid matter is poured out upon 

 the sides of the tongue as it is thrust forth, and 

 this is sufficiently adhesive to attach small insects, 

 such as ants, small grubs, beetles, &c., which are 

 quickly drawn in and swallowed. But as many 

 of the boring larvse are too heavy thus to adhere, 

 and would hold on by their tuberculous feet, or by 

 their strong jaws, the capture of such is effected 



