244 
ANATOMV OF THE HORSE, 
it grows thin and less expansive, and, about opposite to the withers, 
altogether vanishes. The fleshy part (which in its course adheres 
closely to the articulations of the vertebrae with the ribs) is pretty 
uniform in its breadth until it arrives at the withers, opposite to 
which it divides into three tails or portions, of a flattened pyra¬ 
midal form, and so disposed that one, more or less, overlaps 
another. Of these, the inferior division is the direct continuation 
of the common fleshy belly : from it proceed six or seven flat ten¬ 
dons, which go to be fixed to the ribs at their articulations with the 
transverse processes. The middle division sends off' three broad 
thin tendons, to be fixed to the three last transverse processes of 
the neck. The superior division is a small conical slip, ending 
in a slender tendon, which is attached to the same process of the 
fourth cervical vertebra. These tendons are all embedded in, and 
intermediately connected by, continuous fleshy parts, which adhere 
to the costal articulations at the withers, and to the oblique pro¬ 
cesses and sides of the bodies of the three posteriormost vertebrae 
of the neck. 
Action .—It will incline to a state of flexion the fore quarters 
upon the hind ; or the hind upon the fore; according as the one 
or the other are made the fixed points. It is a principal agent in 
the acts of kicking, and rearing, and leaping. If one acts by 
itself, the fore or hind parts of the body will be inclined to one 
side. The pair will also assist in the erection of the neck. 
SPINALIS DORSE 
Situation, —Deep-seated upon the withers. 
Form. —Thick, elongated, pyramidal: base turned down¬ 
wards. 
Attachment .—Posteriorly, through the medium of the aponeuro¬ 
sis of the longissimus dorsi,to the spinous processes of several of the 
posterior dorsal vertebrae : anteriorly, to the spines of the six or 
seven anterior dorsal vertebrae, and those of the three or four pos¬ 
terior cervical. 
Relations .—Externally and superiorly, with the trapezius be¬ 
hind, and complexus major in front ; internally, with the ligament- 
urn nuchae; and, inferiorly, it is inseparably united with the last 
muscle. 
Direction. —Longitudinal. 
Situation. —The broad and thick part is covered by a broad patch 
of inseparably adherent aponeurosis, which grows thin and less ap¬ 
parent posteriorly, but, anteriorly, ends in a broad tendon, which 
pierces the fleshy termination of the belly, and becomes fixed to 
the spine of the last cervical vertebra. 
