OF THE MUSCLES OF THE FACE IN MAN AND IN ANIMALS.
T h e fleshy or muscular part of the animal frame is a peculiar fibrous
substance; and of the various textures, it alone possesses power of
contraction, and consequently of producing motion. In the limbs
and trunk the muscles are distinct and powerful, having their
tendons attached to the bones, and performing the various voluntary
movements. In the face they are more delicate; their action being
merely to operate on the skin, the lips, and eyelids, they require
less power; and that power is not always, as in the muscular exertions
of the body and limbs, directly under the will, but often involuntary
and inseparably united to the conditions or affections of the mind.
It is this latter consideration which gives so much interest to this
subject. By the form of the head we shall presently find that
nature has been provident of an excellence in that organ on which
the mind and superior intelligence of man depend, so in the muscles
of the face there is a provision for a superiority of expression; and