58 THE STOMACH. 



grinding-machine within its body, a fowl, for instance, 

 without a gizzard, would receive no sustenance 

 from the grains on which it depends chiefly for sup- 

 port, since we have seen that until these grains are 

 bruised and crushed, the gastric juice will not act 

 upon the mealy or nourishing matter contained 

 within the husk. And there are reasons for sup- 

 posing, that in this process, nature acts according to 

 certain wise laws, in most cases suiting the quantity 

 and quality of the gastric juice to the necessities of 

 the bird. One of our ablest anatomists*, indeed, 

 concluded that the stomach became more and more 

 fitted to economize the food, as the country to which 

 the bird belongs became less fertile, or less able to 

 provide the requisite supply. In some cases, where 

 the gizzard is imperfect, and is unfitted to act the 

 part of a grinder, the bird is led by instinct to pro- 

 vide itself with a singular substitute. 



We have alluded to the strange matters found in 

 the stomach of the Ostrich which died in this 

 country. Now, the reason why these birds and 

 some others, such as the Emu and Cassowary, 

 which move over the ground by running instead of 

 flying, swallow such strange hard substances, is this: 

 their digestive organs are, generally speaking, weak ; 

 accordingly, their well-known propensity for swal- 

 lowing glass, iron, and other such substances, is an 

 instinctive remedy for this deficiency, which is 

 further assisted by their habits of running ; this 

 motion producing such an increased shaking or rub- 

 Ling together between these hard substances which 

 they swallow, and their natural food, as to render 



* Sir E. Home. 



