TASTE OF CARNIVOROUS BIRDS, 153 



by flying in at the door of a house. We have also 

 seen it strike a pigeon dead from the top of a barn. 

 It is a great destroyer of young game and poultry*." 



The crow feeds, however, occasionally on grain : 

 " I have," says Sir Everard Home, " found grain in 

 its gizzard, but it is not the kind of food of which it 

 is most fond. The crow is by many accused of 

 destroying the grass, by pulling it up by the roots. 

 This is an error arising out of the following very 

 curious circumstance. In searching for grubs which 

 are concealed in the earth, and supported by eating 

 the roots of the grass, the crow pulls at the blade of 

 grass with its bill, and when the grass comes up, the 

 bird knows that there are under it insects which 

 have destroyed its roots, and in this way detects them ; 

 but if the blade of grass is firm, it goes to another 

 part of the ground. In a field where grubs are very 

 abundant, the crows scatter the grass every where, 

 so as to give the appearance of having rooted it up, 

 while they have only exposed the depredations of the 

 insects by which the roots had been destroyed. As 

 the rook lives occasionally upon grain, it was natural 

 to suppose there would be some characteristic dis- 

 tinction between the digestive organs of that bird 

 and those of the crow, whose food is chiefly animal, 

 but upon the most accurate examination no difference 

 whatever can be detected except the cuticular lining 

 being thinner. This leads me to conclude that 

 although the rook does eat vegetable substances, the 

 principle upon which the gizzard is formed is such as 

 to fit it more particularly for the digestion of insects. 

 The gizzard of the raven is like that of the crow. 



" There are many other birds under similar cir- 

 cumstances ; they eat and digest vegetable food very 

 readily, but when the choice is given them prefer that 

 of the animal kind ; and from the weakness of the 

 * Ornith. Diet. p. 11,3, 2d edit, 



