44 THE STORY OF BIRD-LIFE. 



whereas birds with a more generalised kind of 

 beak might possibly obtain food in some other 

 way — as the kea-parrot has done. 



That the form of the beak and tongue is due 

 to the method of obtaining the food, is proved, 

 if proof were needed, by the precisely analogous 

 structures found amongst animals in no pos- 

 sible way related. Thus, the beak of the hawk 

 is matched by the exactly similar beak of the 

 octopus, a marine invertebrate. In both, the 

 organ is used for tearing up living prey. In- 

 stances could easily be multiplied. That the most 

 highly specialised form of beak is derived from a 

 more generalised type is shown from the fact that, 

 humming-birds, spoon-bills, scissor-bills and so on, 

 do not develop their peculiarities till late in life. 



There is at least one instance in which the 

 form of the beak differs in the two sexes. This 

 case is afforded by the Huia bird of New Zealand. 

 That of the male is short and stout, that of the 

 female long, slender and curved downwards. 

 They feed on grubs obtained from more or less 

 decaying wood. The male, with his stouter bill, 

 breaks away the decayed wood and so unearths 

 the concealed grub — this is not a pun ! The female 

 probes the sounder wood and drags out her food 

 by force. Sometimes when the male having 

 cleared away all the decayed wood is yet unable 

 to reach his prey the female is enabled to do so, 

 but, having done so, we are told she retains, 

 perhaps by consent, what she has procured. 



If the beak is important to some birds, the 

 tongue is equally so to others. 



The form and size of the tongue, like every 



