CHAPTER XXIII. 
TOOLS AND TASKS AMONG THE BIRDS. 
We may look at this question of a bird providing 
for its comfort in a more philosophic and helpful way 
than that of simply narrating the kind of food and the 
feeding habits. We see in many groups a general type 
of beaks all adapted to similar uses, as when all birds 
had teeth; but when birds grew older they branched 
into some forms with tools very peculiarly shaped 
(specialized) for specific purposes. Thus the beak of 
the Apteryz, already noted, is very different from that 
of its fellow ostrich forms. 
Now, we can never know whether the ancestors 
of this bird, by some sudden and extensive variation, 
were endowed with a longer beak than the usual clap- 
trap shape of the others and then took to prodding 
with it, or whether it took to prodding first with an 
ordinary beak and by the slightest favorable varia- 
tions developed the present shape. This latter case 
would be an instance where the usual natural-selec- 
tion argument would prevail, as follows: The bird 
having the longest beak would prod the deepest; the 
one with the slimmest, sharpest beak would thrust 
the quickest; the one with the most sensitive beak 
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