55 
Gluteus minimus (Pl, X1. 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 inferior and outer margin of the ilium, and contiguous external surface, as far as 
the origin of the gluteus 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 gluteus magnus. 
A muscle (P]. XI. p.) 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 gluteus 
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 gluteus medius. This muscle and the preceding portion, or 
gluteus minimus, are described by Prof. Mayer* under the names of Gluteus quartus and 
Gluteus 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. 
Ihacus 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 gluteus 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 Meckelt+ says it is wanting in the Cassowary. 
Pyramidalis —The same kind of modification which affects the ilacus 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 gluteus minimus, which 
it opposes, abducting and rotating the femur outwards. 
Adductor brevis femoris (Pl. XI. r)—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. 
Adductor 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 fur Vergleich, Anatomie; 4to, 1889, p. 12. + Arch. fur Physiol. xiii, 261. 
