A FEATHEK. 



IN order to understand how the bird's wing can resist the 

 pressure of the air, we must examine the wing-quill of some 

 large bird. Our Christmas or Thanksgiving turkey may 

 furnish us with a stout wing-feather, or we may pick some 

 up in the parks in summer when the ducks and geese are 

 moulting, or we may, if nothing better can be obtained, pull 

 a feather from the turkey-tail duster, remembering always that 

 we have a tail-feather, not .a wing-feather. But having pro- 

 cured a broad-webbed feather, study it carefully. Kub your 

 finger along the webs to test its elasticity. Notice the effect 

 of pressing it in different directions and observe how it 

 stretches under pressure like a piece of jersey cloth, breaking 

 apart only under rough usage or great strain, and readily 

 being coaxed back into place again. 



What makes the web of the feather so elastic ? The ques- 

 tion is not easy to answer clearly, for a feather is complicated 

 and its parts are minute. With the unaided eye we see too 

 little and with the microscope we see too much. We shall 

 understand best by taking for the first a feather whose parts 

 can be readily made out without a microscope. An ostrich 

 plume, for example, is made up of a multitude of little 

 plumes, called barbs, attached to a quill, or shaft; and each 

 of these barbs is itself a miniature plume with its own shaft 

 and barbs, to which is given the name of barbules. Few 

 feathers show the barbules as plainly as these plumes of the 

 ostrich, but the ostrich's barbules are not connected, so the 

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