52 



3. M. gluteus minimus in the Ostrich is correctly so named, for it 

 is a very small muscle ; it arises from a thin line on the ilium, an inch 

 and three-quarters in length, shown at c, c, Fig. 6, just behind the origin 

 of the iliacus, and is inserted, with the opponens quadrato femoris, be- 

 low the great trochanter, on the front of the femur (Fig. 7) ; its weight 

 is .... 1 oz. 



4. M. biceps femoris has a bony origin, below that of the glutceus 

 maximus on the ilium, and lies along the entire surface of the bone, be- 

 tween that muscle and the semimembranosus, h, h (Fig. 6) ; it is inserted 

 into the tubercle in the middle of the fibula ; its weight is . . . 41 J oz. 



5. M. semitendinosus takes its origin from the bony prominence of 

 the posterior extremity of the ilium, from the tuber ischii, and the 

 membrane that joins these two points, j, j (Fig. 6), and is inserted into 

 the inner margin of the upper and posterior surface of the tibia ; its 

 weight is , . . 14 oz. 



A remarkable accessory muscle arises from 

 the insertion of the adductor magnus (Fig. 7) in 

 the femur, and is fastened into the tendon of 

 the semitendinosus, near its insertion into the 

 tibia. This accessory muscle weighs 1 oz., and 

 runs nearly at right angles to the tendon of the 

 semitendinosus. Its action is to lift and guide 

 the tendon, so as to increase the force of the 

 semitendinosus in propelling the body forwards 

 when the foot is fixed. The mechanical use 

 of this muscle is similar to that of the acces- 

 sor ius flexor i digitorum longo in the sole of the 

 human foot. 



6. M. semimembranosus has its origin on the 

 ilium, below the biceps, as shown at i, i, Fig. 6 ; 

 and is inserted in a line commencing at the top 

 of the tinea aspera of the femur (Figs. 7, 8), and 

 extending to the fascia of the thigh down as 

 far as the inner side of the knee ; its weight 

 is 17 oz. 



The similarity of its use to that of the glu- 

 tceus (1) is shown by the circumstance that it 

 sends a slip (lj oz.) backwards to the sides of 

 the first two or three caudal vertebras, which 

 must be regarded as an additional agitator 

 Cauda. 



7. 8. M. vastus externus is composed of two 

 parts — 



31. v. e. 1. Having an inverted T-shaped 

 origin from the great trochanter, between the 

 insertions of the gluteus medius and minimus 

 (Fig. 7) ; it is inserted on the outer side of the 

 capsule of the knee joint ; its weight is 25 i 



OUTER SIDE OF LEST FEMUR 

 OF OSTRICH. 



a, Insertion of obturator. 



b, Origin- of vastus externus, 



No. 1. 



c, Insertion of glutceus me- 

 dius. 



glut cms mini- 



d, 



oz. 



e, quaclratus femo- 

 ris. 



f, ,, iliocccpsularis. 



g, semimembrano- 

 sus. 



h, Origin of vastus externus, 

 No. 2, 



k, Insertion of adductor 



magnus. 

 I, Origin (A, /3) of fiexores 



digitorum. 

 m, ,, (7), gastrocnemius, 

 n, ,, (A, a) fiexores di- 

 gitorum. ' 

 °> » (fi) gastrocnemius. 



