250 The Bird 



the female comes to his aid and accomplishes what he 

 has failed to do." 



The bill of a bird, besides serving in so many other 

 ways, is invaluable in preening the plumage, arranging 

 disordered feathers, dr}'ing them, and, most important 

 of all, in pressing out the oil from the gland on the lower 

 back, and with it carefulh' dressing all the feathers, giv- 



-^w^l^^W-V^V-ffijiM 



Fig. 194. — Bill of male and female Huia Birds, showing difference of the bill 



in the two sexes. 



ing to them that brightness and gloss and also the water- 

 proof quality — so surely a sign of perfect health in a 

 bird. When, after the bath of a caged bird, you see the 

 drops roll from its feathers, literall}' like " water off a 

 diick's back," then the good health of the bird is certain. 

 The all-important use of the bill as a needle, shuttle, 

 pick and shovel, auger, or trowel in nest-building does not 

 concern us here, nor does its function in expressing emo- 

 tion, or in taking the place of the voice or of the foot. 



