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Glutæus minimus (Pl. XI. c). - Origin. It rises below and internal to the preceding
muscle from the anterior and inferior extremity, and from one inch and three-fourths of
the interior and outer margin of the ilium, and contiguous external surface, as far as
the origin of the glutæus medius; also by some fleshy fibres from the outside of the last
rib. Ins. These fibres slightly converge as they pass backwards to terminate in a broad
flat tendon which bends over the outer surface of the femur, to be inserted into the ele-
vation anterior to the attachment of the glutæus magnus.

A muscle (Pl. XI. D.) which may be regarded either as a distinct accessory to, or a
strip of the preceding one, arises immediately behind it from half an inch of the outer
and inferior part of the ilium; its fibres run nearly parallel with those of the glutæus
minimus, and terminate in a thin flat tendon, which similarly bends round the outer part
of the femur, to be inserted into the outer and under part of the trochanter immediately
below the tendon of the glutæus medius. This muscle and the preceding portion, or
glutæus minimus, are described by Prof, Mayer* under the names of Glutæus quartus and
Glutæus quintus, in the Cassowary; one of them is absent in most birds.

Use. - All the preceding muscles combine to draw the femur forwards, and to abduct
and rotate it inwards.

Iliacus internus. - This is a somewhat short thick muscle, of a parallelogrammic form,
fleshy throughout; rising from the tuberosity of the innominatum in front of the aceta-
bulum immediately below the glutæus minimus, and inserted at a point corresponding to
the inner trochanter, into the inner side of the femur near the head of that bone, which
it thus adducts and rotates outwards. This muscle is present both in the Ostrich and
Bustard, but Meckel† says it is wanting in the Cassowary.

Pyramidalis. - The same kind of modification which affects the iliacus internus, viz.
the displacement of its origin from the inner surface of the ilium to a situation nearly
external, affects this muscle, which, from its insertion and triangular form, I regard as
the analogue of the pyramidalis. It arises fleshy from the outer surface of the ischium
for the extent of an inch, and converges to a broad flat tendon which is inserted into
the trochanter femoris opposite, but close to the tendon of the glutæus minimus, which
it opposes, abducting and rotating the femur outwards.

Adductor brevis femoris (Pl. XI. E). - A small, long and slender muscle arises from the
innominatum immediately behind the acetabulum, passes over the back part of the great
trochanter, becomes partially tendinous, and is inserted into the back part of the femur
in common with the following muscle.

Aductor longus (Pl. XI. XIV. F). - A long, broad and thin muscle, separated from the
preceding by the ischiadic nerve and artery. The origin of this muscle extends one
inch and a quarter from near the upper margin of the innominatum which is behind
the acetabulum; it is joined by the preceding strip, and is inserted into the whole of the
lower two-thirds of the back part of the femur.

* Analekten fu Vergleich. Anatomie: 4to. 1839, p.12. † Arch. fur Physiol. xiii.261.