=Ox.=—The second to the eleventh costo-chondral joints inclusive are
diarthroses with close capsules, reinforced externally. (They are
synchondroses in the sheep.) The upper parts of the cartilages are
attached to each other by distinct elastic ligaments (Ligamenta
intercostalia).
The first pair of chondro-sternal joints are separate from each other;
intercrossing fibers unite the costo-chondral junctions above the
joints.
The first segment of the sternum forms a diarthrosis with the body. The
anterior joint surface is concave, the posterior convex. The joint
(Articulatio intersternalis) is surrounded by a close capsule, and the
joint surfaces are attached to each by a small intraarticular ligament.
Limited lateral movement is possible. (In the sheep the joint is a
synchondrosis.)
Both surfaces of the sternum are covered by a layer of fibrous tissue.
=Pig.=—The second to the fifth or sixth costo-chondral joints are
diarthroses. The intersternal articulation and the sternal ligaments
resemble those of the ox.
=Dog.=—The first chondro-sternal joints do not coalesce.
The internal sternal ligament divides into three bands.