76 
THE HORSE.-NO. 3 
THE HORSE.—No. 3. 
The Anatomy of the Muscles. 
The bones of the whole body constitute a frame¬ 
work to which the numerous muscles (which are 
concerned in, and are the means of the various mo¬ 
tions of the animal) are attached. The bones are 
not smooth, but have an uneven surface, and present 
depressions and elevations; these elevations are 
like nipples, and are called nipple-shaped processes, 
or tubercles. Into these depressions and on to these 
tubercles, the muscles are attached. The bones are 
levers, and the power of their motion is the muscles. 
In our discussion we propose to direct attention 
mainly to those bones and muscles only which are 
concerned chiefly in the travelling, carrying, and 
drawing motions of the horse. These bones and 
muscles are mostly those of the body and legs, and 
consequently the body and legs, in their bony and 
muscular anatomy, will be treated of. We content 
ourselves with an enumeration of the bones of the 
head, as the head is only in a small way employed 
in motion or draft. The power it has over either 
arises from its elevation or depression. When the 
horse increases his pace he lowers his head, if it be 
free; when he is called on for greater exertion in 
draft, he also lowers his head. Without this de- 
ression of the head, and that to the level of the 
ody, the horse cannot reach the height of his 
speed, nor the utmost of his power of draft. In 
ordinary motion or draft, the head is not so low as 
the level of the body; it is only in his higher and 
more powerful exertion, in either speed or draft, 
that the horse brings his head to the level. It is 
then the position of the head, and not its power, 
which is concerned in motion or draft. Consequent¬ 
ly, in animal mechanics, it is relatively of small 
consequence. The head is not even held up in its 
natural position by the muscle, but by a strong liga¬ 
ment or cord called the pack-wax, which is at¬ 
tached to the head at one end, and on the withers 
at the other, and thence into the muscles of the 
back. When, however, the head is to be depressed, 
the muscles of the neck and shoulder are called on 
to do it. Thus the bones and muscles of the neck, 
as w T ell from their shape as from their size, are of 
importance in the power of the horse for motion. 
Muscles of the Neck. —We shall first consider the 
muscles of the neck. They lie chiefly in the lower 
part of the neck, and end in tendons at or near the 
head. Those concerned in the raising and lowering 
of the head and turning it in various directions, make 
a complicated system. Two of the most important of 
them are the splint-like muscle and the large compli¬ 
cated muscle. The splint-like muscle constitutes the 
bulk of the neck on its upper side, c, fig. 15, and is at¬ 
tached to all the bones of the neck except the upper 
one, called the atlas, nearest the head. From this 
muscle a tendon goes to and attaches itself to the 
atlas and the bones of the temples. Its office is to ele¬ 
vate the head and neck, and for this it is very pow¬ 
erful, as it must needs be; upon it depends the beauty 
of the neck. As it is more or less developed, so will 
the neck be more or less arched, but it should be 
light above, and large below and at the junction of 
the neck with the shoulder. From it arises the 
thickness and muscularity of the neck, and if full 
at the lower part and light at the upper part of the 
neck* the neck itself, when joined well to the head, 
will be perfect. Clumsy necks arise from too much 
cellular substance or fat, and not from this muscle, 
as also do lofty crests. Mares and geldings have 
rarely clumsy necks or lofty crests. 
The large complicated muscle is the largest and 
most powerful in the neck. It arises from the five 
lower bones of the neck, and makes the bulk of the 
lower part of the neck, d, e, fig. 15; at its upper part, 
as it nears the head, it lessens its bulk and unites in 
part with the same tendon as the splint-like muscle, 
but is principally joined to the bone of the back part 
of the head. It assists to raise the head and neck, and 
it is particularly concerned in raising and thrusting 
forward the nose. When too powerful, it makes 
the nose stick out, and deforms the horse. The 
martingale is used to counteract the force of this 
muscle. When this muscle is very large and the 
splint-like one quite small, the horse will be ewe- 
necked, hollowed (or at least straight) above and 
projecting below. In such a neck the nose protrudes 
and can hardly be got down. 
The small complicated muscle, the straight, and 
the oblique muscles of the upper part of the neck, 
attached mainly to the two upper bones of the neck, 
a, fig. 15, are also employed in raising the head. 
One of the muscles used to lower the head is at¬ 
tached to the breast bone, and lies next to the skin ; 
it proceeds up the neck, and near the head changes 
into a tendon, and is inserted into the lower jaw near 
its angle, b, fig, 15. It is used to bend the head to¬ 
wards the chest. Another muscle concerned in low¬ 
ering the neck springs from the back of the head and 
the first or four upper bones of the neck, and the 
pack-wax proceeds downward, mixes with the mus¬ 
cles of the shoulder, and attaches itself to the lower 
shoulder bone ( [m , in fig. 11, p. 48); it also assists 
in raising the shoulder. 
The muscles of the neck are all double (in pairs), 
one on each side of the neck. To raise or depress 
the head they must act together. To turn the head 
and neck to one side, one only must act, on the side 
to which the head and neck are to be turned; if an 
elevating muscle, then they will be raised and turned 
at the same time ; if a depressing muscle, then low¬ 
ered and turned. Thus is provision made for every 
kind of motion of the head and neck. 
