280 THE MUSCLES. 



of its special insertions ; this reduces the total number of interosseous muscles to seven 



four dorsal and three palmar. 



" These small muscles arise from the lateral faces of the metacarpals to the lateral 

 and upper portions of the first phalanges. By their contraction, they incline these 

 phalanges laterally, and consequently carry the corresponding digit inwards and 

 outwards." 



It may be added that the lumbrici muscles are small muscular and tendinous 

 fasciculi annexed to the tendons of the deep flexor of the phalanges, and whose tendons 

 terminate on the external side of the four last digits in becoming blended with the 

 interossei. 



ARTICLE III. MUSCLES OF THE POSTERIOR LIMBS. 



These form four principal groups : the muscles of the croup, thigh, leg, 

 and foot. 



MUSCLES OF THE GLUTEAL REGION OR CROUP. 



This region is composed of three superposed muscles, which are applied 

 to the ilium, and are distinguished according to their relative situation as 

 the superficial, median, and deep glutens. 1 



They are covered by a thick fibrous fascia, a prolongation of the aponeu- 

 rosis of the great dorsal, and which is continued backwards over the muscles 

 of the posterior crural region, where it is confounded with the superficial 

 lamella of the fascia lata. This gluteal aponeurosis is fixed to the external 

 angle of the ilium and the supersacral spine. By its deep face it gives 

 attachment to several fasciculi of the superficial and middle glutei. 



Preparation. 1. Place the animal on its side, or, better, in the second position. 

 2. Remove the skin from this region in order to show the gluteal aponeurosis, and to 

 study its extent, attachments, and relations. 3. Cut away this aponeurosis to expose 

 the anterior point of the middle gluteus and the muscular portion of the superficial. 

 To prepare the aponeurotic portion of the latter muscle, the sacro-sciatic insertion of the 

 long vast us must be detached by the scalpel and thrown downwards. 4. Incise the 

 superficial gluteu^near its femoral insertion., and reverse it on the sacral spine, so as to 

 lay bare the external face of the middle or principal gluteus. 5. Divide this muscle near 

 its femoral insertions, taking care not to injure these, and remove the whole of its mass, 

 studying meanwhile the nature of its relations to the parts it covers ; the deep or small 

 gluteus then becomes apparent, and may be conveniently examined. 



1. Superficial Gluteus. (Fig. 129, 4.) 



Synonyms. Ilio-trochanterius medius Girard. Gluteus minor Bourgelat. Gluteus 

 medius Rigot and Lafosse. The gluteus magnus of Man. (Gluteus externusPercivall. 

 Ilio-trochanterius externus Leyh.} 



Composition Situation. This muscle is composed of a fleshy portion, 

 situated beneath the gluteal aponeurosis, and an aponeurotic portion entirely 

 concealed by the anterior portion of the long vastus (abductor magnus 

 Percivall). 



Form and Structure. The muscular portion is triangular, and most 

 frequently divided into two branches, an external and internal, by an ex- 

 cavation which deeply indents its superior border. Its constituent fasciculi 

 are very thick, loosely attached to each other, and are all directed back- 

 wards and downwards to converge into a flat tendon, which terminates the 

 inferior angle of the muscle. The aponeurosis likewise terminates the in- 

 ferior angle of the muscle. This aponeurosis, also triangular, is con- 



1 For the justification of the employment of these new denominations see note, 

 page 177 



