112 
The Bird 
It may seem to us that the mandibles, the jugal, the 
palate, the quadrates, the ear-bones, and the hyoid are 
an unmeaning jumble of irregular bones, apparently 
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bearing no relation to one another, 
and with absolutely no interest 
outside the fact that each is very 
well suited to its particular use. 
If scientists had studied only the 
bones of adult animals, we might 
have groped in vain for any an- 
swer to the question of how these 
bones came to be what they are. 
But the science of embryology, or 
egg-life, has unfolded wonderful 
things, and, as we shall soon see, 
nothing more marvellous than the 
strange story of these bones. 
The eel-like lampreys which 
crowd up our shallow brooks in 
April to spawn are curious crea- 
tures, and not the least remark- 
able thing about them is the fact 
that they have no jaws, although 
they have an elaborate cartilagi- 
Fic. 86.—Gill-basket of Lamprey. noygs net-work protecting and 
supporting the gills. 
We perhaps thought that every 
vertebrate animal in the world had jaws of some kind, and 
perhaps even lampreys had them long ago, before their 
habit of sucking did away with any need for chewing. 
But the reason I have spoken of the lamprey is because 
