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ANATOMY OF THE HORSE. 
number to the ribs, and like them increase in length from the 
first to the ninth or tenth, after which they progressively de¬ 
crease ; but this is liable to variation : the first cartilage is re¬ 
markably short. Those belonging to the true ribs are in 
general not very long, but broad, thick, and resisting ; those 
proceeding from the false ribs are on the contrary mostly very 
long and comparatively slender, and incapable of offering much 
resistance—are in fact so formed and connected that they admit 
of considerable motion. 
THE BREAST-BONE. (STERNUM.) 
Conformation, The sternum (being a single bone) is symme¬ 
trical in its form, shaped, altogether, like the keel of a ship; 
posteriorly, flattened from above downwards; anteriorly, from 
side to side. It is composed of seven irregularly formed bones, 
and of the ensiform and'cariniform cartilages. 
Division. Into four surfaces and two extremities. 
The Superior and Inferior Surfaces are pyramidal in figure, 
being broad posteriorly, contracted into borders anteriorly : the* 
former, slightly concave, terminates between the cartilages of 
the two first ribs; the latter, irregularly convex, ends in the ca¬ 
riniform cartilage. 
The Lateral Surfaces are broader anteriorly than posteriorly. 
The three foremost bones present broad, superficial, lateral con¬ 
cavities ; the four hindermast, projecting lateral borders, which 
incline downwards and form the boundary lines between the in¬ 
ferior and lateral surfaces. The indentations upon the fore and 
hind parts of the separate bones, form, in the united state, 
lateral concavities for the reception of the cartilages of the ribs : 
the hindermost bone, itself, receiving two entire cartilages. 
The Extremities are constituted of projecting cartilages.— The 
Cariniform Cartilage, arising in a curve from the inferior border, 
forms a prominent and remarkable convexity in front, flattened on 
either side, and affords attachment to the sterno-maxillares and 
sterno-thyro-hyoidei.—The Xiphoid or Ensiform Cartilage is 
fixed to the lavSt bone, and assumes a form in some measure 
correspondent therewith, being broad and flattened above and 
below : it is terminated however by a thin border, to the figure 
of which it owes its name, though this is subject to much 
variation. . . 
GENERAL REMARKS ON THE THORAX. 
Form, That of a truncated cone slightly incurvated, the 
