The =scapula= is very wide, the index being about 1 ∶ 0.7. The spine is
triangular and is very wide in its middle, which curves backward over
the infraspinous fossa and bears a large tuberosity. Its lower part
bears a small projection (rudimentary acromion). The anterior border is
strongly convex in profile, sinuous when viewed from the front, and
thick and rough in its middle. The posterior border is wide, slightly
concave, and bears an outer rough lip. The vertebral border is convex,
and the cartilage is not so extensive as in the horse and ox. The
cervical angle is thin and bent inward a little. The dorsal angle is
thick and is about a right angle. The neck is well defined. The rim of
the glenoid cavity is rounded and not notched. The tuberosity is just
above the antero-internal part of the glenoid cavity and bears no
distinct coracoid process.
The =humerus= has an appearance in profile somewhat like an italic _f_
minus the cross-bar; this is due to the marked backward and forward
inclination of the proximal and distal ends respectively. The shaft is
decidedly compressed from side to side. The internal surface is
extensive and flattened; it is separated from the anterior surface by a
distinct border, and bears no teres tubercle. The musculo-spiral groove
is shallow. The deltoid tuberosity is small, and there is a larger
rounded eminence midway between it and the external tuberosity. The
nutrient foramen is on the posterior surface below its middle. The head
is more strongly curved and the neck better marked than in the horse or
ox. The external tuberosity is very large and extends upon the front of
the extremity. It is divided into two high prominences by a wide deep
groove. There is a third eminence below and externally for the
attachment of the supraspinatus muscle. The bicipital groove is at the
front of the inner side; it is undivided and is almost converted into a
canal. The outer groove on the distal articular surface is so shallow as
to give the appearance of two condyles of similar size. The olecranon
fossa is very deep, and the plate of bone which separates it from the
coronoid fossa is thin and sometimes perforated. The proximal end unites
with the shaft at three and a half years, the distal at one year.
The =radius= is short and narrow, but thick. The shaft increases in size
from above downward. The greater part of the posterior surface is in
apposition with the ulna; this part is marked by a vascular furrow which
runs downward from the upper interosseous space, and has the nutrient
foramen at its proximal end. The bicipital tuberosity is represented by
a rough area. The distal end is relatively large. Its carpal surface
consists of concavo-convex facets for the radial and intermediate carpal
bones. There is a wide shallow groove on the middle of the front. The
proximal end fuses with the shaft at one year, the distal at three and a
half years.
The =ulna= is massive. It is much longer and considerably heavier than
the radius. The shaft is curved. The anterior surface is convex and most
of it is rough and attached to the radius by the interosseous ligament.
There is a smooth area on the upper third, which concurs with the radius
in forming the upper interosseous space, and is marked in its upper part
by the nutrient foramen. From this space a vascular furrow passes
downward to the lower part of the shaft, where there is often a distal
interosseous space for the passage of vessels. The internal surface is
extensive, concave, and smooth. The external surface is slightly convex,
and its upper part is marked by an oblique rough line or ridge. The
proximal extremity is large and is bent inward somewhat; its length is
more than one-third of that of the entire bone. The distal extremity is
relatively small; it articulates with the ulnar and accessory carpal
bones, and is notched in front to accommodate the ridge on the radius.
The bone contains a considerable medullary canal. The bone is
consolidated at three to three and a half years.
The =carpus= comprises eight bones, four in each row. The bones of the
proximal row resemble those of the ox, with the exception of the
accessory, which is more like that of the horse, but has no external
groove. The first carpal is small, elongated from before backward,
rounded, and articulates in front with the second carpal. The latter is
high and narrow, and articulates with the second and third metacarpal
bones below. The third carpal articulates with the radial and
intermediate above, the third metacarpal bone below. The fourth is the
largest bone of the row; it articulates with the intermediate and ulnar
above, the fourth and fifth metacarpals below, and bears a tuberosity on
its volar aspect.
[Illustration: