224 THE STORY OF THE BIRDS. 
into each other in some birds that even dissection is 
puzzled to separate them. 
(25) If the bill is strongly hooked and a flat, skin- 
like membrane (cere) is across it on top near the head, 
your bird is either a bird of prey or a parrot. 
(26) If a Birp or Prey, there are never two toes 
permanently in the rear, and the claws tend to be very 

Head of vulture. Head of a hawk. 
sharp and curved, or else the nostrils are perforate 
and head naked. 
(27) If the head is wholly naked, nostrils perfo- 
rate, it is a VULTURE. 
(28) If the head is not wholly naked, and the eyes 
are on the side of the head, or else the nostrils open 
through the cere and the outer toe does not bend 
back easily by the rear one, it is a Hawk or EaGue. 
(29) If the eyes are far forward, with a feathered 
disk around each; or the nostrils open at the edge of 
the cere, and the outer toe easily turns back by the 
rear one, the bird is an Owt. 
One owl has a hawklike face, but its nostrils are 
within the cere, and has its feet feathered to the 
claws, a tendency not strong in the hawks. 
The owls all have the outer toe capable of turn- 
