14 



Forest Birds. 



running along the concavity of the bone, and as 

 this muscle contracts, it straightens the sheath and 



FIG. i. 



Head of Green "Woodpecker, showing sheath passing round 

 head, and joined to skull in nostril. 



From nature. One-half natural size. 



so forces out the tongue to a considerable distance 

 beyond the point of the bill (Fig. 2). Thus when 

 the bird sees an insect in a hole or under the bark, it 



FIG. 2. 



Head of Woodpecker, showing tongue extended and (G) gland, 

 from nature. One-half natural size. 



shoots out its wormlike tongue and transfixes the 

 insect, the barbs preventing its prey from slipping 



