WINGS AND FEET 



bodies has been exhaustively studied by naval 

 architects, and it has been shown that a prop- 

 erly shaped body completely submerged under 

 ideal circumstances with the wave eliminated 

 meets with little resistance besides friction. 

 The fact that a loon when swimming rapidly 

 on the surface is apt to depress its body in the 

 water so that its back is awash seems to favour 

 this contention. It may be argued that the 

 bird does this to avoid observation or to escape 

 being shot, but it certainly swims faster when 

 thus submerged. Under water the diving bird 

 has a great advantage in being able to assume 

 a shape best adapted to cleaving the liquid 

 medium. 



Incidentally it may be remarked that the 

 loon, in perfecting its legs for use under water, 

 has disabled itself for walking on the land, 

 but as it usually builds its nest on or close to 

 the water, it can well afford to sacrifice ter- 

 restrial locomotion. 



The combined use of wings and feet, a 

 reptilian form of progression, would naturally 

 be found among birds that had not fully 

 specialized in either direction. Among living 

 birds the cormorant and the penguin represent 

 203 



