110 The Bird 
the upper mandible, which bone we may call the jugal. 
Indeed when we come to look closely at the quadrates 
we find that they are very important, and in addition to 
supporting the bar of bone from the upper jaw, and 
pivoting the lower jaw, they bear another pair of bones 
Fra. 85.—Columella in ear of Snowy Owl (magnified 2 diameters). 
extending inward from them, beneath the skull, to the 
broad thin palate or roof of the mouth. 
In a chicken the individual movement of the upper 
jaw is not very great, but in some birds, such as parrots, 
it is much more noticeable. With a sharp knife we can 
entirely detach the upper and lower jaws of most birds, 
without cutting through a bone, the connection consist- 
ing only of exceedingly tough tendons. When we found 
our shark’s skull we perhaps wondered what had become 
