48 THE ANATOMY OF YERTEBRATED AXIMALS. 



m,ajo7\ passing from posterior dorsal or lumbar vertebrae — tLe 

 pyriformis from sacral vertebrae — the femoro-coccygeiis (when 

 it exists) from caudal vertebrae — to the femur, are all hypo- 

 skeletal muscles, without homologues in the anterior extremity. 



All the other muscles of the limbs are i?itri7isic^ takinnr 

 their origins from the pectoral or peivic arches, or from some 

 of the more proximal segments of the limb-skeleton, and hav- 

 ing their insertion in the more distal segments. They are 

 thus arranged in Man and the higher Marti'inalla : 



Intrinsic muscles proceeding from the pectoral or pelvic 

 arches to the humerus or femur ^ on the dorsal aspect. — In the 

 fore-limb, the deltoides proceeds from the clavicle and scapula 

 to the humerus. This superficial shoulder-muscle continues 

 the direction of the fibres of the trapezius ^ and, when the 

 clavicle is rudimentary, the adjacent portions of the two mus- 

 cles coalesce into a cephalo-humeralis muscle. Beneath the 

 deltoid the supra-spinatus^ on the pre-axial side of the spine 

 of the scapula ; the infraspinatus, and the teres major and 

 minor, on its post-axial side, run from the dorsal aspect of the 

 scapula to that of the head of the humenis. 



In the hind-limb, the tensor vagince femoris, which passes 

 from that part of the ilium which corresponds with the spine 

 and acromion of the scapula, to the femur, appears to answer 

 better to the deltoid than does the glutceus maximus, which, 

 at first sio-ht, would seem to be the homoloo*ue of that muscle. 



The iliacus, proceeding from the inner surface of the crest 

 of the ilium to the smaller trochanter, answers to the supra- 

 spinatus y the glutams medius and m,inimus, which arise from 

 the outer surface of the ilium, to the infra-sp>inatus and teres. 



In the fore-limb, a muscle, the subscapidaris, is attached 

 to the inner face of the scapula, and is inserted into the hu- 

 merus. No muscle exactly corresponding with this appears 

 to exist in the hind-limb. 



On the ventral as^^yect in the fore-limb, the coracohrachialis 

 pass.es from the coracoid to the humerus. In the hind-limb, a 

 number of muscles proceed from the corresponding (ischio- 

 pubic) part of the pelvic arch to the femur. These are, from 

 the outer surface of the pubis, the p>ectineus, and the great ab- 

 ductors oi the femur; with the obturator exter?ius, from the 

 outer side of the ischiopubic fontanelle, or obturator membrane. 

 The getnelli and tlie quadratus fenioris take their origin from 

 the ischium. 



No muscle is attached to the proper inner surface of the 

 ilium, so that there is no homologue of tlie subscapularis in 



