THE BEAK. 407 



varies the nature of the bird's food. It is plain 

 that an eagle provided with the bill of a duck 

 would prove, if we except his talons, not a very 

 formidable foe. And again, if the duck were fur- 

 nished with the beak of an eagle, it would be of 

 little service to it, in its hunting up the muddy 

 waters in search of food. We may glance at a few 

 of these varieties among the different tribes of birds. 

 The beak of the birds of prey which is repre- 

 sented in the accompanying 

 diagram is very peculiar, and 

 in itself conveys an idea of 

 strength, ferocity, and of a 

 martial character. In these 

 birds the beak is very strong, curved, sharp -edged, 

 and sharp-pointed. The upper of the two divisions 

 of the beak, which are called " mandibles," is the 

 longer, and is hooked at the end, and often has a 

 sort of tooth at the sides. By means of this formi- 

 dable instrument, which is moved by powerful 

 muscles, the bird tears its prey with the greatest 

 ease. The hooked tip and sharp over-hanging edge 

 of the upper mandible are admirably adapted for 

 taking a firm hold, and also for dividing asunder 

 the soft parts of the prey. This sort of beak is 



