98 SOME SUGGESTIONS FOE BIRD STUDY. 



External Features. 



With this preliminary caution we may proceed to 

 examine the body of a bird for adaptational features. 

 Birds are creatures of the air. Their bodies are heavier 

 than air, yet they maintain themselves in it, often for very 

 long periods, with grace, ease, and comfort. Kecall the 

 long migrations performed in amazingly short periods of 

 time. It is well to recall these things with the children 

 before familiarity with aeroplanes has killed all wonder 

 and done away with the mystery of the birds' mastery of 

 the air. 



What is the shape of a bird's body ? Look at the birds 

 perched on the fences or trees. If a stuffed bird is avail- 

 able, examine it closely. Best of all try to catch glimpses 

 of a bird from below as it sails gracefully overhead. 

 Watch the gulls wheeling above you at the estuary, on the 

 rocks, or around the ploughed fields ; or the rooks with 

 heavy flap of wing high overhead wending their way home 

 at even. Here a fieldglass will help you to answer with 

 conviction the question : What is the shape of a bird's 

 body ? A bird's body is spindle or torpedo shaped. It is 

 long, rounded, tapering evenly to both ends. Here you 

 may enlarge on the suitability of such a form to rapid and 

 easy progress in air, how it is calculated to reduce friction 

 and offer a minimum of resistance. At this point refer to 

 remarks in lesson on the Swimming Fish (p. 67). 



Feathers, 



Note next the covering of the bird's body. You may 

 have in your hand a freshly killed bird, which may have 

 been the occasion of your taking a bird's body as your 

 theme, or a stuffed specimen may stand in front of you, 

 or a live bird in a cage. Of course you will not talk about 

 details without the material at hand for examination and 

 verification. 



Birds are feathered. This feature alone separates them 

 from all other types of life. Feathers are outgrowths of 

 the epidermis. Feathers are light, proverbially o ; they 



