64 BRITISH BIRDS. 



they can distinguish them by sight, so that if one has in 

 its bill a delicate morsel, it is likely that some of his 

 companions will eagerly strive to partake of the luxury. 



Another curious circumstance appears in connexion 

 with feeding. ^V^lenever a granivorous, or grain-eating 

 bird, in a state of nature, is caught and killed, the crop 

 and gizzard are found, on being opened, to contain a 

 quantity of small pebbles and other hard substances ; 

 and it is said, instinct causes the birds to swallow them. 

 Now, of about a thousand birds reared by the machine 

 in lofts and rooms, with bushels of fine gravel lying in 

 heaps and scattered about, none would eat it, though 

 several died in consequence of not doing so, by becom- 

 ing crop-bound. Here then instinct failed. It appears, 

 therefore, that as children insensibly acquire, by receiv- 

 ing from their parents such food as they soon learn to 

 relish, and by observation and habit find agreeable to 

 their stomachs and palates, so birds learn to choose and 

 mix their peculiar food. But as, without parents to 

 direct, few children would choose to eat the most whole- 

 some, preferring to live on the pleasant rather than the 

 useful, so these birds having no parents, though many 

 endeavours were made, could not be persuaded to eat 

 stones, though necessary for their existence. 



Most of the birds thus reared, were very fine and 



