TASTE OF GRANIVOROUS BIRDS. 129 



ferred that, under certain circumstances, grass and 

 other herbs are rendered easy of digestion arid yield 

 their utmost possible nutriment without trituration. 

 It certainly is not a little singular that the stomachs 

 of carnivorous animals, which can digest even the 

 hardest bones, cannot act upon grass, a fact exem- 

 plified in the dog; for when he eats grass, as he 

 sometimes does by way it is supposed of a medicine, 

 he either ejects it again or it passes through his intes- 

 tines altogether unaltered. 



The interesting facts furnished by comparative 

 anatomy seem to authorize the inference that the 

 varieties of structure, more particularly of the solvent 

 glands, are for adapting the bird to the supply of 

 provisions afforded by the country it inhabits. Every 

 one of these glands, accordingly, produces a secretion 

 fitted for the digestion of all the different kinds of 

 food, and whatever complexity is found in the organs 

 is chiefly for the purpose of economizing the food, 

 by preventing it from escaping till it is thoroughly 

 digested. In addition to the instances which we have 

 already mentioned. Sir E. Home gives the following 

 illustrations. 



" The cassowary of Java (Casuarius Emeu, 

 LESSON), as it lives in the most luxuriant country in 

 the world, has its digestive organs adapted to such 

 abundance. The gullet is unusually large : it dilates 

 into the cardiac cavity, which is a direct continuation 

 of it, and is everywhere studded over with small 

 gastric glands of a simple structure : these are- 

 placed on each side in oblique rows, which terminate 

 in a middle row, extending the whole length of the 

 cavity. The termination is marked on the lower 

 part by the commencement of the lining, which covers 

 the whole internal surface, being very thin for a 

 little way, as well as upon the anterior part, becoming 

 thicker and thicker posteriorly, where the cavity of 

 the gizzard is situated. There is an oblique valvular 



