48 ' Bird - Lore 



These paragraphs, however, are not intended for a discourse on terraria, 

 but on what may be learned from a captive bird. One need not wait for some 

 wild bird to be brought into the school before giving a lesson, for a Canary or 

 a domestic hen will serve the purpose equally well and can, therefore, be fitted 

 in during the winter months when other opportunities for bird-work are scarce. 

 —A. A. A. 



THE BIRD AS A FLYING-MACHINE 



With Photographs by the Author 



There can be no doubt that one of the most wonderful cases of adaptation 

 to be found in all nature is that of the flying bird. The modifications which 

 the entire structure of the bird has undergone in its development from the 

 ancient lowly reptile have been controlled primarily by the requisites of an 

 efficient flying-machine. Other needs have been sacrificed or made subservient 

 to the requirements of flight, so that today, except for degenerate forms, the 

 bird stands as the ideal heavier-than-air flight mechanism. It is little wonder 

 that man, in his endeavor to learn to fly, went to the bird and tried to invent 

 wings that would lift him from the ground. But wings, alone, do not make the 

 bird nor account for its ability to defy the action of gravity. A man with wings 

 is no more a bird and capable of flight than is a hat because it has feathers. 

 It is not alone the fact that birds have wings that makes them capable of flight 

 but it is the hundreds of little and big adaptations of their bodies, their legs, 

 their tails, their heads, their very bones that lift them from the ground and 

 drive them successfully through the air. It was not until these principles 

 were thoroughly understood and applied that a real successful aeroplane was 

 invented. 



One cannot, of course, study the mechanism of flight with a captive bird in 

 a terrarium or hope to explain in detail to children all the principles involved, 

 but if one bears in mind a few of the principles that governed Mother Nature 

 in moulding the bird so that it could fly, it will make the study of the structure 

 of a bird fascinating rather than dry and uninteresting. When one visits a 

 museimi or a large aviary where birds from all parts of the world are assembled 

 together, one is at first led to believe by their various sizes and shapes that they 

 have little in common except wings and feathers. But when one examines them 

 at all critically, he discovers that the apparent diversity of form is quite 

 superficial, and that down underneath they are all fundamentally alike. Their 

 different methods of securing food have given rise to different bills and feet, 

 which we may consider at another time, but aside from these conspicuous parts, 

 their structure is very similar. Let us see, therefore, what are the main re- 

 quirements of an aeroplane and how these are met by the bird. 



I. Lightness : Above all else, a flying-machine must be light. The materials 

 used must be as light as compatable with strength and there must be no 

 unnecessary materials or parts. So, in a bird, we find, developed from the crude 



