MUSCLES OF THE HAUNOH. 401 
internal part of the head of the inner small metacarpal bone. Action—to 
flex the leg. 
FLEXOR METACARPI INTERNUS is situated on the postero-internal side of 
the arm. Origin—from a ridge behind the internal condyle of the 
humerus. Jnsertion—to the head of the os metacarpi parvum: previous 
to its insertion, it enters a sheath formed by the annular ligament. 
Action—to flex the leg. 
FLEXOR PEDIS PERFOLANS ET PERFORATUS is situated on the posterior part 
of the arm. Origin—common to both muscles, from a ridge on the heel 
process of the internal condyle of the humerus. Jnsertion—of perforatus 
bifid, to the external and internal border of the supero-posterior part cf the 
os corone. Insertion—of perforans ; after receiving a strong bundle of 
ligamentous fibres from the posterior carpal ligament, it pierces the two 
divisions of the flexor perforatus, opposite the pastern, and spreading out 
is attached to the postero-inferior part of the os pedis. Action—to flex 
the knee, and bend the fetlock and pastern joints. 
ULNARIS ACCESSORIUS is deeply seated at the posterior part of the 
arm. Origin—from the whole of the internal concave surface of the 
ulna. Jnsertion—to the tendon of the flexor pedis, with which it blends. 
Action—to assist the perforans and pertoratus in flexing the knee, &c. 
EXTENSOR SUFFRAGINIS is situated on the postero-external part of the 
fore arm. Origin—from a tubercle in the posterior and external part of 
the radius ; from the above bone as far down as the ulna reaches, and 
from the shaft border of the ulna. Jnsertion—to the supero-anterior part 
of the os suffraginis, and to the capsular ligament of the fetlock joint. 
Action—to extend the fetlock. 
EXTENSOR METACARPI OBLIQUUS is situated on the infero-anterior part 
of the arm. Origin—from the infero-anterior and outer part of the 
radius, extending as high up as the middle. Jnsertton—after passing 
underneath the tendon of the extensor pedis, and over the tendon of the 
extensor metacarpi magnus, to the supero-anterior part of the os metacarpi 
internum, -Action—to confine the tendon of the extensor metacarpi in its 
place during action and to extend the leg. 
RaDIALIS ACCESSORIUS is situated on the infero-posterior part of the 
arm. Origin—from the posterior part of the middle of the radius. Jn- 
zertion—to the tendon of the perforans, which it joins opposite the carpo- 
metacarpal articulation. Actvon—to assist the perforans. 
MUSCLES OF THE HAUNCH. 
THE DIFFICULTIES experienced by the student in distinguishing the 
muscles of the shoulder are as nothing when compared with those he will 
encounter in making out the muscles of the haunch. ‘The latter are firmly 
connected together by fascia, so that their fibres must be divided by the 
knife in order to make them agree with any description which is given of 
them by comparative anatomists. To comply with the desire to retain 
the names used in human anatomy, this has been done to 4 most ridicu- 
ous extent; but unfortunately, as the analogy is very slight, the imagina- 
tion of the dissector has been called into play and different anatomists 
have pursued a varied nomenclature, to the great annoyance of the student. 
Thus the triceps abductor femoris of our text is the biceps of Percivall, 
and the long vaste of Chauveau, but it should either be regarded as one 
large mass of muscle, in common with the semi-membranosus and semi- 
teuclinosus, or if it is divided from them it must itself be described as 
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