DIGESTION. 145 



of the water contained in these reservoirs, which they al- 

 ways find to be pure and wholesome. It is stated by those 

 who have travelled in Egypt, that camels, when accustomed 

 to go journeys, during which they are for a long time de- 

 prived of water, acquire the power of dilating tlie cells, so 

 as to make them contain a more than ordinary quantity, as 

 a supply for their journey.* 



^ When the Elephant, while travelling in very hot weather, 

 is tormented by insects, it has been observed to throw out 

 from its proboscis, directly upon the part on which the flies 

 fix themselves, a quantity of water, with such force as to 

 dislodge them. The quantity of water thrown out is in pro- 

 portion to the distance of the part attacked, and is common- 

 ly half a pint at a time: and this, Mr. Pierard, who resided 

 many years in India, has known the elephant to repeat eight 

 or ten times within the hour. The quantity of water at the 

 animaPs command for this purpose, observes Sir E. Home, 

 cannot, therefore, be less than six quarts. This water is not 

 only ejected immediately after drinking, but six or eight 

 hours afterwards. Upon receiving this information, Sir E. 

 Home examined the structure of the stomach of that animal, 

 and found in it a cavity, like that of the camel, perfectly 

 well adapted to afford this occasional supply of water, which 

 may, at other times, be employed in moistening dry food for 

 the purposes of digestion.* 



In every series of animals belonging to other classes, a 

 correspondence may be traced, as has been done in the jNIam- 

 malia, between the nature of their food and the conformation 

 of their digestive organs. The stomachs of birds, reptiles, 

 and fishes, are, with certain modifications, formed very much 

 upon the models of those already described, according as the 

 food consists of animal or of vegetable materials, or presents 

 more or less resistance from the cohesion of its texture. As 

 it would be impossible, in this place, to enter into all the de- 



* Home, Lectures on Comparative Anatomy, vol. i. p. 171. 

 t Supplement to Sir E. Home's Lectures on Comparative Anatomy, vol. 

 vi. p. 9. 



Vol. II. 19 



