The Senses 209 
thousands of birds are annually hurled against these 
objects to their destruction.” 
A bird’s eye is very large in proportion to the size of 
its head, and is correspondingly perfect and delicate in its 
workings. It rests in a deep cavity hollowed out of the 
skull, and is protected by soft cushions of fat and controlled 
by bands and pulleys of muscle which control its motions. 
Looking closely at the eye of a live bird, we at once 
remark its brightness—that alertness of expression which 
so truly reflects the virile life of these creatures. The 
eye, more than any other part of a living organism, is 
an index to the relative power of its intelligence—more 
surely than all the other facial features taken together. 
The eyes of a sloth are expressionless black spots, and 
even those of an orang-utan are bleary and watery. 
But a crow or magpie, or any other bird you may choose, 
though with horny, shapeless lips, nose, and mouth, looks 
at us through eyes so expressive, so human, that no won- 
der man’s love has gone out to feathered creatures through- 
out all his life on the earth. A dog is a four-legged, hairy 
animal with the eyes of a bird. 
The eye of a bird appears perfectly round, and is 
composed of a central area of black, encircled by a ring, 
sometimes hardly distinguishable from the inner divi- 
sion, or again it may be highly coloured. The circular 
centre or pupil is always of a uniform black, and no won- 
der, for “it is not a thing—it is the hole in a thing.” As 
when we look through the lens of a camera, only the 
blackened inside of the bellows is reflected to us, so in 
the eye of a bird, the delicate living lens, itself invisible, 
