For these birds swim as penguins do, when submerged. Why, 

 then, did the penguin suffer the loss of the use of his wings 

 for flight ? 



This question leads to another. Why did that giant 

 razor-bill known as the great auk beeome flightless ? It 

 would seem that its wings somehow failed to keep pace with 

 the growth of its body, so that while they remained sufficient 

 for flight under water, they became useless for flight in the 

 air. Its failure in this led to its extinction, for it was unable 

 to escape from its arch-enemy, man. When the old-time 

 sailors, somewhere about one hundred years ago, discovered 

 its haunts in Iceland could be profitably invaded for the 

 purpose of collecting feathers, and bait, they speedily wiped 

 out the race ; for being flightless they were unable to escape 

 the marauders once they had effected a landing. Unhappily 

 there was no Bird Protection Society in those days to stop 

 this senseless slaughter. 



Here our survey of Birds on the Wing ends. It began 

 with flight through the air, it ends with flight through the 

 water. It is not a little surprising, surely, to find that the 

 same wing can be efficiently used for both these extremes of 

 motion. And stiU more surprising to find that, this being 

 so, the penguin should have been forced,- so to speak, to adopt 

 the expedient of evolving a paddle ; and so forgo the power 

 of aerial locomotion. The skeleton of this wing, it was 



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