NATURAL HISTORY. 



309 



Sight is the most perfect and most delightful of all the 

 senses. It fills the mind with the largest variety of ideas, 

 converses with objects at the greatest distance, and continues 

 tht longest in action without being satiated." SPKCTATOE. 



naturalist can infer the one from the other with unerring 

 certainty. 



986. Examples of the agreement between the formaticn of the beak and the food 

 of the bird are furnished as follows : Sea-birds, which feed on fish too large to 



be swallowed at a mouthful, are furnished 

 with a large beak, hooked at the end. 

 But this instrument, is much longer, atid 

 therefore less powerful, though sufficiently 

 so relatively to their prey. When birds 

 feed on such fishes and reptiles as are 

 small enough to be seized and easily 

 swallowed, the beak is straight, still 

 greater in length and resembling a pair of 

 pincers, as those of the martin pecker, 

 fig. 1. Birds living on insects as the 

 bee-eater, fig. 2, have slender and very 

 long beaks, either straight or very slightly 

 hooked, except when they catch their prey 

 in flight, as do the swallow and the 

 goatsucker, fig. 3, in which the bill is 

 short, broad, deeply cut, so as to enable 

 tb - em to present a large mouth to receive 

 their prey. Birds which live on grain, on 

 the contrary, such as the sparrow, 

 fig. 4, have a short, thick bill, con- 

 vex above, or conical, and in general 

 straight, the upper mandible not 

 projecting over the lower. A singular 

 modification of this organ of prehen- 

 sion is presented in the case of the 

 3 4 pelican, which has a membranous 



receptacle, consisting of a pouch or pocket, attached to its lower mandible, in 

 which it collects prey, which it swallows afterwards at leisure. (See 942.) 



987. Why have the eyes of birds a greater facility for 

 discerning near or distant objects than those of other animah ? 



Because, in the first place, birds in general procufe their food 

 by the aid of their beak ; and, the distance between the eye and the 

 point of the beak being small, it becomes necessary that they 

 should have the power of seeing very near objects distinctly. 



On the other hand, from being often elevated much above the 

 ground, living in the air, and moving through it with great 



