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ANATOMY OF THE HORSE. 
‘ —In the back and loins the holes of conjugation are situated 
immediately behind the transverse processes; and the lumbar 
vertebrae alone possess lateral vertebral grooves, but which are 
very narrow compared with those along the neck. 
Extremities —Broad and articulatory. The anterior excavat¬ 
ed to receive the occipital condyles ; the posterior, transversely 
oblong, presents three smooth surfaces for articulation with the 
sacrum. 
Vertebral Canal —Capacious and semi-oval along the neck ; 
transversely oval and small along the back ; semi-circular along 
the loins, and of greater diameter than in the back, less than in 
the neck. United, anteriorly, with the cavity of the cranium; 
continuous, posteriorly, with the sacral canal. Containing the 
spinal marrow and its membranes. 
II.—THE CHEST. (THORAX.) 
The thorax or chest is the ample conoid cavity constituting 
the anterior part of the trunk, formed by the ribs laterally and 
the sternum inferiorly, in which are contained the organs of re¬ 
spiration and circulation. 
THE RIBS. (COST^.) ^ 
Number. Thirty-six; ranged in pairs, 18 on either side : 
occasionally there exist 38, and even 40 ribs. They are distin¬ 
guished by their numerical order, counting from before back¬ 
wards, 
^Conformation. In general similar : they are elongated, curv¬ 
ed or twisted, convex along their outer sides, concave along 
their inner, and taking a direction from within outwards and 
from above downwards; they vary however in their length, de¬ 
gree of curvature, and obliquity of direction. 
Division. Into true or sternal ribs, and false or asternal; the 
former, nine in number, being those whose cartilages are actu¬ 
ally inserted into the sternum; the latter, the remaining nine, 
being only connected therewith through the intervention of 
others. Each rib possesses two extremities, two surfaces, and 
two borders. 
Extremities. The superior or vertebral comprehends—1. The 
head, the protuberant or antero-superior portion, presenting 
two convex smooth surfaces, for articulation with the bodies of 
the vertebrae between which it is received, and these divided by 
a rugged notch, into which is fixed the interarticular ligament 
of the head. 2. The neck, the contracted part, supporting the 
