I 24 The Bird 



of a bird, mention was made of the two long bones which 

 branched out from the rear of the tongue and which are 

 all that remain of the third ancestral gill-arch. In the 

 Flicker, the slender, white tongue divides into these two 

 branches just in front of the glottis and from here they 

 extend backward, passing one on each side of the wind- 

 pipe, and on upward, following the curve of the skull, 

 then forward, h'ing together upon the forehead. Not 

 even here do they end, however, but actually reach some 

 distance into one nostril! So when this bird stretches 

 out its tongue, the tips of the rear branches leave the 

 opening of the nose and shoot around over the surface 

 of the skull until they have gone as far as possible. No 

 wonder the poor ants have but little chance when a 

 Flicker visits their hill and sets the marvellous mechanism 

 of his tongue rapidly to work. And no wonder the 

 enthusiasm of an ornithologist never fails, when he thinks 

 of the scores of similarly interesting structures still await- 

 ing investigation. 



The tip of the tongue in the sap-sucking woodpeckers 

 is beset with numerous hairs forming a brush-like instru- 

 ment, but spines take the place of hairs in the species 

 which feed exclusively on insects. It is known that the 

 exact proportion of insects in the diet of any particular 

 kind of woodpecker is reflected in the more or less per- 

 fect adaptation of the minute structure of its tongue to 

 that end. 



In the sapsuckers, too, the tongue is comparatively 

 short, doubtless because the sap flows readily from the 

 holes which these birds bore. Hence they require no 



