CHAPTER XVI 



How THE Birds Know 



THOSE creatures tliat crej)! from prehistoric 

 sliine, later developinj^' featliers, are older 

 than man. Tliese early birds liad heavy 

 jaws, teeth set in sockets, clawhl^e fingers on tlie 

 first wing joint, and long, jointed tails having 

 feathers running down each side. Coming down 

 through the ages since that time, our birds of 

 to-day have lost their teeth through lack of ne- 

 cessity for them; have developed such power of 

 flight that the wing claws have become useless 

 and vanished until they are now represented by 

 only a tiny, blunt tip at the first joint; the encum- 

 bering jointed tail has contracted in almost every 

 species to an inch or less of tiny, ckjsely set verte- 

 brae, while miraculous power of flight has devel- 

 oped. 



Birds that remained on the water evolved flat, 

 boat breasts for swimming, grew webbing between 

 their toes to make them efficient paddles, and 

 shovel-like bills for scooping up wet, wormy food. 

 In sharp contrast with them, the birds of the shore 

 line grew narrow, slender bodies, extremelj^ long 

 legs developed from constant wading, no webbing 



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