156 DIGESTION. 



This is the case with fowls and birds. The giz- 

 zard is, in effect, their stomach ; and in some birds it 

 is capable of grinding the hardest substances, with 

 the assistance of a liquor nature has provided in it. 

 The gravel, which makes a part of their food, is to 

 assist the operation of this mill. 



B. This explains the marvellous stories related of 

 the ostrich. There was an account not long since, of 

 one whose stomach was found quite full, among other 

 articles, of such indigestible materials as old nails, 

 glass, and brass buttons, which were partly worn 

 away by the friction of the organ. 



A. The camel, to enable it to traverse the sandy 

 desarts of the countries in which it lives, is kindly 

 furnished with an extraordinary kind of stomach, 

 which answers among other purposes that of a water 

 vessel, in which it can carry its drink. There are 

 several little muscular cisterns attached to the stom- 

 ach of the animal, which are kept separate, and which 

 it fills from time to time as opportunities serve. The 

 main stomach has, (principally on one side,) rows 

 of purses or cells, side by side, with their mouths 

 upwards, in length from six to nine inches, which 

 are capable of admitting one's hand, and of holding 

 from one pint to a quart of water or more. These 

 purses or cells are numerous, and capable of holding 

 when much distended, nearly thirty gallons of water. 

 When the creature is thirsty the stomach contracts, 

 and the water flows over the tops of the cells into the 

 main stomach, to moisten the dry food, and help di- 

 gestion. The greater the quantity of food there is in 



