17 



the first phalanx. The small subclavian artery, about the size of a crow- 

 quill, runs between the clavicle and first rib, and so passes down to 

 nourish the upper extremity. 



But, as the great characteristic endowment of the ostrich is its 

 enormous power of running, we find that the muscles of its hinder limbs 

 are those which are pre-eminent in point of development ; these are 

 exposed when the integument and the subjacent strong fascia are raised. 

 Under the skin in the thigh, two large veins, an external, and an inter- 

 nal saphena, are traceable. Covering the whole of the posterior part of 

 the hip and thigh, an enormous, triangular, flat, fleshy muscle is brought 

 into view, which seems to consist of three parts — the upper third, or 

 tensor vaginae femoris, the middle, or glutaeus maximus ; the inferior, or 

 the depressor caudae ; the whole mass arises from the posterior edge of the 

 ilium as far forwards as the commencement of the symphysis iliaca, 

 and as far backwards as the side of the tail. The tensor vaginae femoris 

 runs forwards, downwards, and outwards, converging to form a flat 

 tendon, which passes over the anterior and external surface of the knee, 

 where it unites with the anterior and lateral heads of the gastrocnemius, 

 and partly is inserted into the head of the tibia along its anterior edge ; 

 the middle third, or glutaeus, is inserted along with the last, and by a 

 small musculo -tendinous slip unites with the vastus externus beneath. 

 The depressor caudae is hardly separable from the posterior border of the 

 glutaeus maximus, and is inserted into the lowest border of the tendons 

 of the two upper portions. 



On removing this enormous covering, the deeper muscles are exposed. 

 Sartorius — a square, thick mass — arises from the outer side of the upper 

 and anterior part of the ilium, and from the spines of the lumbar verte- 

 brae; the fibres run downwards, forwards, and outwards, to be inserted in- 

 to the side of the ligamentum patellae, and the upper portion of the inner 

 condyle of the tibia, and by a fascial expansion to the inner condyle of the 

 femur. Glutaeus medius — a triangular fan-shaped muscle — arising from 

 a large space on the ilium, almost the whole of its external surface as 

 far back as the acetabulum ; the fibres converge, and run outwards to 

 form a flat tendon, which is inserted into a pit on the upper and outer 

 part of the great trochanter. The tendon passes over a bursa on the 

 summit of the trochanter, and is attached to the origin of the vastus 

 externus. The tendon of this muscle commences between two planes of 

 muscular fibre. Glutaeus minimus is a small pear-shaped muscle, arising 

 from the upper and anterior portion of the ilium, superior and anterior 

 to the acetabulum ; its fibres converge, run backwards and outwards, and 

 are inserted into the anterior ridge at the root of the great trochanter, 

 posterior and inferior to the glutaeus medius, and beneath a tendinous 

 arch, formed by the origin of the vastus externus. 



Opponens quadrato -femoris, or ilio-capsular, is a remarkable, well- 

 marked, triangular, fleshy slip, arising from the ilium, anterior and infe- 

 rior to glutaeus medius, and superior and anterior to the glutaeus minimus; 

 the fibres run outwards, to be inserted into the same line as the last named 

 muscle, and are united to it by a tendinous slip. The nature of the homo- 



e. i. a. peoo. — vol. ix. n 



