These muscles, surrounding the eyelids of the horse, account for
the superior expression of the eye. The muscle d seems to be calculated
to operate upon the outer angle of the eyelids, and to
enable the animal to direct the eye backwards: in this it is probably
assisted by the muscle e .
F. This forms a class of muscles which descend on the side of the
face, and are inserted into the nostril.
&. g. Muscular fibres, also operating in the distention of the tube
of the nostril.
h . A strong muscle, which acts upon the cartilage, and distends
the nostril with great power.
There is something in the distribution of these muscles which
illustrates the character of the class, and accounts for the peculiarity
of expression. We cannot fail to observe the difference in the
general direction and classing of the muscles of the face in the
horse and in the dog. In the carnivorous animal they all tend to
lift the bps from the canine teeth, so that they cannot act without
showing the teeth with the snarling expression; here, on the contrary,
muscles having the same place and origin pass to the cartilages
of the nose, and inflate it the instant that they are excited.
It is therefore these muscles, more than any other circumstance
that produce the very different character and expression of the two
classes of animals, the Carnivorous and Graminivorous.
i. A strong muscle, which lies under those of the nostril f . Its
tendon passes forward over the nose, and unites with its fellow
of the other side. These together form a broad tendon, which
is inserted into the upper lip. There is a similar muscle
moving the lower lip, which cannot be seen in this view.
l. m. The circular fibres of the bps, which in the horse are particularly
strong and fleshy.
n. A web of muscle, which is extended from the cutaneous muscle
of the neck.
The muscles i. k. l. m. have all great power, and give extensive
motion to the bps. k. is the tendon of the muscles of the
upper bp, which I have called D e p a s c e n t e s : it takes this
course over the nose in a manner quite pecubar to this class
of animals, to raise and project the bp as in gathering its food.
Any one who feeds his horse from his hand may feel the singular
sensitiveness and mobility of his bps.
Looking to these muscles, and contrasting them with the animated
sketch above it, we cannot fail to see how much the form of
the head has to do with the teeth—small forward, and large and
deep set m the back part of the jaw; and how much the peculiarity
of expression of the animal is owing to the breathing through the
nostril, and not through the mouth; and to the brilhant eye placed
on the utmost projection of the head, and which, by the slightest
turn of the pliant neck, is directed backward; and, finally, how the