British Ornithology, 287 



The tail usually consists of twelve feathers, sometimes ten 

 or fourteen, and in the gallinaceous order, eighteen. 



The senses of touch and taste must be very weak, the claws 

 c^nd feet being covered with a hard skin, approaching in some 

 species to a homy or scaly substance ; but the deficiency in 

 these two senses is compensated by great acuteness in the 

 remaining three. 



The eye is furnished with a thin membranaceous veil, which 

 the bird can draw and remove at pleasure, easily discernible 

 in the hawk tribe. Its probable use is to guard the eye in 

 rapid flights, or to moderate the effect of light. By a peculiar 

 additional mechanism, birds are also enabled to regulate the 

 sight for near or distant vision. 



The digestive organs merit particular notice. The throat 

 terminates in a large membranaceous bag, called the crop*. 

 Here the food is collected and softened, preparatory to its pass- 

 ing into the gizzard, where it is reduced to a pulp. This organ 

 consists of two very powerful muscles, lined and covered with 

 a strong tendinous coat, furrowed within. In rapacious birds, 

 the gizzard is, however, wanting, their stomach being nearly 

 allied to those of quadrupeds. The power of this organ almost 

 exceeds belief, it having been proved by experiment, that very 

 hard and sharp substances are unable to resist its action* 

 It has been observed, that stones which birds are in the habit 

 of swallowing are seldom known to pass with the faeces. They, 

 therefore, probably contribute to their health by affording an 

 additional supply of calcareous matter; and digestive organs 

 of this singular character are consequently requisite for the 

 purpose of pulverizing them sufficiently for admission into 

 the system. 



The channel conveying air to the breast is called the Trachea, 

 and differs from that of other animals. The organ producing 

 sound is situated immediately below the point where the trachea 

 separates into two channels, and is called the Larynx inferior; 

 so that a bird might emit its characteristic note after decapita- 

 tion. \ J* S. 



• It is of so light and close a texture, that the crops of tiirkies are 

 prepared and sold in London as small balloons ; when filled with hydro- 

 gen gas they will rise with great rapidity, and retain the gas for a consi- 

 derable time, particularly if slightly varnished. 



