Wings 333 



that this restriction and disuse have been to subserve some 

 good and useful purpose,— food perhaps being more easily 

 obtained, or enemies avoided by terrestrial or aquatic 

 locomotion. Functional radiation, working always for 

 the good of the race, once gave to all birds the power of 

 traversing the globe, passing high over sea and land; but 

 later this was withdrawn, until in some cases their wings 

 have become a mockery. The wings of the Owl Parrot 

 of New Zealand are of full size, but the muscles are so en- 

 cased in fat that the}^ are useless for flight. These par- 

 rots feed on ground-mosses, and being nocturnal and 

 tnerefore having few enemies, their onh' use for wings 

 is occasionally to sail gently to earth, like a Flying Squir- 

 rel, from the trees in the hollows of which they some- 

 times roost. For this purpose their flabby muscles are 

 perfectly suited. 



The Spotted Tinamou of South America is one of a 

 number of birds which have not quite lost the power of 

 flight, but in which, as in the first attempts of a young 

 bird, almost no control is possessed over the direction 

 or height of their flight. In fact, the condition is much 

 the same as that of a man in an ordinary balloon, who 

 is at the mercy of the wind and the sustaining power of 

 the gas. Hudson gives the following interesting account 

 of this bird: "It is an exceedingly rare thing to see this 

 bird rise except when compelled. I believe the power 

 of flight is used chiefly, if not exclusively, as a means of 

 escape from danger. The bird rises up when almost trod- 

 den upon, rushing into the air with a noise and violence 

 that fill one with astonishment. It continues to rise 



