THE ANATOMY OF A BIRD 23 



bird the tongue is rolled up so as to form two tubes running side by 

 side, and the same power of sucking up juices is acquired by this 

 means, which, curiously enough, is exactly paralleled by the pro- 

 boscis of the butterfly. In other birds the tongue is sometimes merely 

 a thin, flat, horny projection, and in others, again, it is just not 

 absent altogether. 



A little reflection about the habits of birds will show that they 

 really do not want teeth ; and we know that Nature is a most rigid 

 economist : nothing superfluous is allowed in the body. Even 

 rapacious birds like Owls and Hawks have no teeth, because they 

 have a powerful beak and claws, with which the food may be as 

 effectually torn to pieces. Birds such as the Pigeon, which feed upon 

 grain, possess a gizzard — which we have had something to say about 

 already — that performs effectually the function of a mill, grinding 

 into a powder the hard grains of wheat and other seeds which the 

 bird swallows. Nevertheless birds once did possess teeth. In 

 earlier times of the history of this earth there were some birds 

 whose jaws had as formidable a range of teeth as the mouth of 

 many reptiles. They were fish-eaters, and have been named 

 Hesperornis and Ichthyornis. The first was something like a Diver 

 in shape, the latter more like a Gull. A still more ancient bh-d, the 

 oldest form of bird known to us, the Arcliceo;pteryx, had also toothed 

 jaws. In fact, in the old days it was the rule for birds to have teeth, 

 whereas now it is the rule, without a single exception, for birds to 

 be toothless. Perhaps these ancient and extinct forms had some 

 corresponding disadvantage when compared with their modern 

 representatives ; their teeth and claws, for example, may have been 

 less effective. But although there is no bird now living which has 

 real teeth, traces of these organs have been discovered in the young 

 embryos of certain birds, which seems to be an absolute proof that 

 they, at any rate, had for their first parents toothed birds. But 

 although modern birds have no teeth, with enamel, dentine, and so 

 forth, all complete, the horny beak has occasionally ridges which to 

 some extent play the part of teeth. The inside of the Duck's mouth 

 is rough with such ridges, which occur also in some other birds. 

 The large Flamingo was for some time regarded as a long-legged 

 and awkward Duck that had partially adopted the habits of a Stork, 

 partly on account of the fact that the inner edges of the beak were 

 ridged in a fashion exactly like that of the Duck. But it happens 

 that there is a Stork, a true Stork, in India, whose scientific name 

 is Anastomus^ which has similar ridges. Ducks feed to some 



