I have found that in the composition of the human body as compared
with the bodies of animals the organs of sense are duller and
coarser. Thus it is composed of less ingenious instruments, and of
spaces less capacious for receiving the faculties of sense. I have
seen in the Lion tribe that the sense of smell is connected with
part of the substance of the brain which comes down the nostrils,
which form a spacious receptacle for the sense of smell, which
enters by a great number of cartilaginous vesicles with several
passages leading up to where the brain, as before said, comes down.

The eyes in the Lion tribe have a large part of the head for their
sockets and the optic nerves communicate at once with the brain; but
the contrary is to be seen in man, for the sockets of the eyes are
but a small part of the head, and the optic nerves are very fine and
long and weak, and by the weakness of their action we see by day but
badly at night, while these animals can see as well at night as by
day. The proof that they can see is that they prowl for prey at
night and sleep by day, as nocturnal birds do also.

Advantages in the structure of the eye in certain animals (828-831).