Feathers 31 



feathers which were apparently as perfect as any we may 

 examine to-day. When some form of scale had once 

 changed so that it was of use in flight, the hollow elastic 

 vane took first place at once, and all intermediate stages, 

 which perhaps had been acquired merely for warmth, 

 went to the wall. A creature could have flight if pro- 

 vided with perfect feathers, or it could retain its scales 

 and find existence possible along the old reptilian planes 

 of life, but no awkward scale-flutterer could long be 

 tolerated. All through the evidences of evolution we 

 find instances like this, — a change for the better beginning 

 slowly, through many channels, then the one best suited 

 forging ahead with inconceivable swiftness, and crushing 

 out all other less adapted structures. Hence the rarity 

 of "missing links." 



Feathers are certainly among the most beautiful 

 objects in Nature; and when we learn a little about their 

 structure, they will be still more interesting. No matter 

 how closely we may examine them, with hand-lens or 

 microscope, their beauty and perfection of structure only 

 increase. If we study a feather, say from the wing of a 

 pigeon, we see that its whole structure is subservient to 

 two characteristics — lightness and strength. What won- 

 derful elasticity it has! We can bend the tip so that it 

 touches the base and it will spring back into shape with- 

 out breaking. 



If we look close!}', we will see that each feather is 

 composite — feathers within feathers. The quill gives off 

 two rows of what are called barbs which together form 

 the vane of the feather; each of these barbs has two 



