INTRODUCTORY CHAPTER. 15 



tion through a resisting medium, as well as in supporting them 

 during their long and laborious flights. 



Birds as well as quadrupeds may be distinguished into two 

 classes, carnivorous and granivorous ; and some may be con- 

 sidered as holding a middle rank, and partaking of both. The 

 carnivorous kinds are distinguished by the length of their wings 

 and the strength of the muscles by which they are moved ; their 

 strong hooked bills, and their formidable claws ; all admirably 

 adapted to the purpose of procuring their food. Their heads 

 are larger, and their necks shorter, than those of other birds : 

 their thighs are strong and brawny, and their sight is so acute, 

 as to enable them to discover their prey from immense elevations 

 in the air, upon which they dart with an astonishing velocity and 

 undeviating aim. 



Carnivorous birds, like carnivorous beasts, have but one 

 stomach, and their intestines are much shorter than those of 

 such as are granivorous. The latter have, in addition to the 

 crop, or stomach where their food is moistened, a second sto- 

 mach, called the gizzard, in which the digestion is completed. 

 This is composed of two hard and strong muscular substances, 

 and its extraordinary powers in comminuting the food would 

 exceed the bounds of credibility, were they not attested by in 

 controvertible facts, the result of experiments made by Spalauzani, 

 who proved that the stomachs of turkeys and common poultry, 

 had the power of breaking to pieces and digesting glass, tin, and 

 iron. Some of the experiments of this naturalist, however, seem 

 to be of too cruel a nature to be proposed for imitation ; and it 

 does not appear consistent with the will of the Great Author of 

 Nature, that we should indulge our*curiosity, or acquire at the 

 best a useless knowledge, by tortures inflicted on any of his crea- 

 tures ; especially as without such means, the multifarious variety 

 displayed both in the physical and moral world, is sufficient tc 

 exercise the greatest genius, and the most indefatigable re- 

 search. 



It is remarkable that birds of the granivorous kind frequently 

 swallow a number of small stones, which are often found in their 

 stomachs, and which assist digestion by grinding down the 

 grain and separating its parts. 



Between carnivorous birds and carnivorous quadrupeds, there 

 seems to be a visible analogy both in their structure and dispo- 

 sition. Both are provided with weapons of rapine and destruc- 

 tion : their manners are fierce and unsocial, and they seldom 

 herd together like those of the granivorous class. Rapacious 

 birds retire to the tops of sequestered rocks, or the depths of 

 extensive deserts, where, like the predaceous quadrupeds, they 

 conceal themselves in gloomy solitude. The granivorous tribes. 



