THE FEATHER MAN 235 



would correspond to the vane is called the *bar- 

 bules. ' 



"Now, let me slide this other lens in, which 

 doubles the magnifying power. If you look 

 closely, Shan, you'll see that barbules are not the 

 same on both sides of the barb. Those pointing 

 towards the tip of the feather are ribbon-shaped 

 for half their length and then form a series of 

 little tiny hooks; those pointing away from the 

 tip are also ribbon-shaped half-way but then they 

 form a series of little troughs or catches. If you 

 look very carefully, you can see that the hooks of 

 the outer barbules link into the catches of the 

 inner barbules next to them, much in the fashion 

 of a hook-and-eye. Can you see that?" 



"Yes," said Shan, after several attempts, "I 

 think I see it now. ' ' 



"Well," continued his instructor, "when you 

 pull the vane of a feather, j^ou pull all those little 

 hooks out of their catches. It isn't a question of 

 their being glued together. And, if you'll notice, 

 the feather will resist a considerable strain before 

 it pulls apart. That 's due to the amount of play 

 in the barbules, and it is that interlocking system 

 which gives a bird's feather its elasticity and air 

 resistance. 



