Feathers ai 
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 closely, 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 
