342 The Bird 



is lost, — all the flexibility of wrist and elbow. \\'ith 

 these propellers the penguins fly through the water, with 

 almost the identical motion of a bird in the air. Though 

 it is usually asserted that the wings move alternateh^, 

 this was never the case with a pair of Black-footed Pen- 

 guins which I carefidh' observed. As regards the speed 

 of swimming, I found that one of these birds, though in 

 bad health at the time and so weak that it could take 

 but a few steps on land, was able to progress under water 



Fig. 271. — Penguin swimming with its wings. 



consideral)h' faster than a man could walk an equal dis- 

 tance on land. The greatest speed was about seven miles 

 an hour; but I have no doubt that when in full health 

 this rate can be far surpassed. 



Surely no fairy-tale can match the mar\'ellous evo- 

 lution of a penguin's wing : fin becoming hand, hand 

 evolving into wnng, and wing reacting to the environ- 

 ment of long ago and again taking on all the outward 

 characteristics of a fin! 



