22 BRITISH BIRDS 



canal is totally wanting. Now the difference between the gizzard of 

 the grain-eating fowl and the flesh-eating hawk is chiefly a matter of 

 diet. The celebrated anatomist, Jolin Hunter, who lived in the last 

 century, and wrote so much about the anatomy of all kinds of 

 animals, including birds, found that he could feed a soft -stomached 

 bird into one with a hard gizzard, and vice; versa. 



We can pass briefly over the rest of the alimentary system, 

 which does not vary a great deal in different birds. The intestines 

 are always rather short, and are diversely coiled, the method of 

 coiling being often characteristic of a particular group. A good way 

 down the intestine are a pair of cseca, which may be entirely absent, 

 as in the Hornbills, for example ; and if present may be extremely 

 short, as in the Sparrow, or very long, as in the Ostrich ; various 

 intermediate degrees exist. As in all vertebrated animals, two 

 glands pour their secretion into the intestine ; these are the pancreas 

 and the liver. The secretion of the liver is the bile ; this fluid is 

 accumulated as it is formed in a largish bag — the gall-bladder, in 

 those birds which possess one. Shakespeare used the epithet 

 pigeon-livered,' which meant literally the absence of a gall-bladder ; 

 but , oddly enough, there are some kinds of pigeons which have a gall- 

 bladder, while others, like the common pigeon, have not. The intes- 

 tine ends in the cloaca, which is the common chamber into which 

 the urinary and generative organs also open. 



Tongue and Teeth. 



In the inside of a bird's mouth we find only one of the two things 

 iliat we might expect to find : there is a tongue, but no teeth. We 

 shall come back to the teeth immediately. The tongue is not so use- 

 ful among the majority of birds as it is in most mammals. But 

 some do make use of it to a great extent. If you watch a parrot 

 eating its food, you will observe that its thick and fleshy tongue is 

 of the greatest assistance in helping it to manipulate the pieces ol 

 food — to extract, for instance, the kernel from a seed or nut. It 

 plays exactly the same part as it does with us. In one kind of parrot; 

 called the ' Brush-tongued Parrakeet,' the tongue is frayed out at 

 the free end into a brush-like extremity. And there are some small 

 birds, which peck at flowers and live upon honey, in which the 

 tongue is thin and delicate, and frayed out in the same way ; this 

 allows them to suck up the juices of the flower. In the Humming- 



