For these birds swim as penguins do, whensubmerged. 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 become 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 still 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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