HIS EYES AND EARS 101 
than it is, in other words, they are like magni- 
fying glasses, or microscopes, so that a tiny in- 
sect ego, that we can hardly see, looks very big 
to a warbler. 
Stranger still, when a bird is far off, his eyes 
are like telescopes. That is, when a hawk is 
soaring about far above the earth, he can see a 
mouse on the ground as well as if he had a tele- 
scope to look through. And the gulls who sail 
about over the shore, and follow steamers on sea 
voyages, can see small fish and tiny bits of 
bread thrown out by the passengers, even when 
they are lost to us in the foam made by the 
vessel. 
Mr. Frank Bolles had a pet barred owl, and 
used to take him out with him. He says that 
the bird’s sight was wonderful, better than bis 
own aided by a strong glass. Many times the 
bird would see and watch a hawk so far off that 
Mr. Bolles with his glass could not see him until 
he came nearer, and_then he looked no bigger 
than a dot against the sky. 
There is a story told of some small birds mi- 
erating over the island of Heligoland, suddenly 
coming down in a flock on to a man’s garden, 
and beginning at once to work among the 
leaves as if they were feeding. 
The owner of the garden knew they did not 
