290 PROF. OWEN ON THE ANATOMY 



A single extensor (PI. XXXIV. fig. 1. v), almost equally tendinous and delicate, arises 

 from the scapula, and represents the ' long extensor' of Vicq. d'Azyr : it is inserted into 

 the rudimental olecranon. 



There is a tendinous trace of a flexor («') and extensor [x] of the minute monodactyle 

 manus : but the motions of the rudimental wing and its terminal hook would seem to 

 be produced as much by the cutaneous muscles which converge to be inserted into the 

 integument connected with it, as by the feeble representatives of the true wing-muscles 

 above described. 



Muscles of the Posterior Extremity. 



The most superficial of the muscles on the outer side of the leg is that very broad 

 one which combines the functions of the tensor vacjince and rectus femoris, but which, in 

 the opinion of both Cuvier' and Meckel^, is the homologue of the tensor vagina and glu- 

 t(Eus maodmus (seu externus) ; since however it is exclusively inserted into the leg, I shall 

 describe it with the other muscles moving that segment of the posterior extremity. The 

 removal of this muscle, of the sartorius, and the biceps cruris, is requisite to bring into 

 view the true glutei. 



GluteBus externus (PI. XXXII. a). — The external glutaus [gluteBUs medius of Meckel) is 

 smaller, as in most Mammalia, than the middle glutteus, but is relatively larger in the 

 Apteryx than in birds of fiight, in which it is described as the pyriformis by Cuvier'. 

 This muscle, however, besides its origin from the outside of the pelvis, overlaps part of 

 the gluteus medius, and has its insertion into the femur at some distance below the great 

 trochanter, all of which are marked characteristics of the glutceus magnus. Origin. It 

 takes its origin from the superior margin of the os innominatum, extends along an inch 

 and a quarter of that margin, directly above the hip-joint, and is chiefly attached by 

 distinct short tendinous threads, which run down upon the external surface of the mus- 

 cle : it rises also by carneous fibres from the external surface of the os innominatum for 

 three lines below the superior margin. Insertion. The fibres converge and pass into a 

 tendinous sheet, beginning on the external surface of the muscle half-way down its 

 course, which ends in a broad, flat, strong tendon, inserted into a rising on the outer 

 side of the femur nearly an inch below the great trochanter. It abducts and raises the 

 femur. 



Glutaus medius (PL XXXII. b). — Origin. This is the large, triangular, strong and thick 

 muscle, which has an origin of three inches' extent from the rounded anterior and superior 

 margin of the ilium, and from the contiguous outer surface of the bone for an extent vary- 

 ing i'rom an inch to eight lines. Ins. Its fibres converge to a strong, short, broad and flat 

 tendon, implanted in the external depression of the great trochanter, having a bursa mu- 

 cosa interposed between the tendon and the bony elevation anterior to the depression. 



1 Le9ons d'Anat. Comp. ed. 1836, torn. i. p. 502. '' Vergleich. Anat. 1828, Tb. iii. p. 361. 



3 Loc. cil. p. 503 ; it is here called 'pyramidal.' 



