3G ANATOMY OF VERTEBRATE 8. 



the c entogluteus, 5 fig. 12,/, the ' quadratus femoris,' the c obturator 

 extcrnus,' the ' obturator interims,' the 6 gemclli,' and the f pyra- 

 uiidalis '- -present a disposition similar to that which they have in 

 the human body. 



The muscles passing between the pelvis and the lesser tro- 

 chanter, and also those that arise from the pubis to be implanted 

 into the internal surface of the thigh, are the ' psoas magnus,' the 

 ( iliacus,' the ' pectmseus,' and the ' tri])le adductor,' fig. 12, p. 



The flexor muscles of the leg are the ' biceps flexor cruris,' the 

 ' semimembranosus,' the ' semitendinosus,' the ' sartorius,' the 

 ' gracilis,' and the ' poplitaeus,' all of which are enclosed by the 

 dense fascia of the thigh, which is kept tense by the action of a 

 6 tensor vaginae femoris.' The last-named muscle, called also the 



o 



4 musculus fascia? latie,' arises from the anterior portion of the 

 crest of the ilium, whence it descends obliquely downward, en- 

 closed between two layers of the fascia, covering the thigh, into 

 which it is strongly inserted. 



The extensor muscles of the leg viz., the ' rectus,' fig. 11, A, 

 the ( vastus internus,' fig. 12, 7, the f vastus externus,' fig. 11, n, 

 and the ' cruraeus ' offer in all quadrupeds the same general dis- 

 position as in Man, the three last forming one great common 



muscle, e trifemoro-rotuleus.' The anterior margin of the thio-h 



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is formed by the ( sartorius,' which here, from its position and 

 office, has been named by hippo tomists the ' long adductor of the 

 thigh.' 



The ' biceps cruris ' arises by a single origin, which is derived 

 from the ischium, and the neighbouring ligaments and fascial ex- 

 pansions. This muscle covers a large proportion of the outer 

 surface of the thigh : its principal insertion is into the head of the 

 fibula, but it likewise throughout its whole length contracts ex- 

 tensive and important attachments with the fascia lata, so that it 

 also becomes a powerful extensor of the thigh. There is, how- 

 ever, a distinct portion of the biceps derived from the sacro- 

 sciatic aponeurosis, the fibres of which are directed obliquely from 

 before backward, which, meeting the ischiatic portion at an 

 angle, form with it a kind of raphe, which is prolonged for some 

 distance. This muscle is called ( vastus longus ' in Hippotomy. 

 The ' gracilis,' fig. 12, u, is a very considerable muscle; it is 

 called by hippotomists the ( short adductor of the thigh,' whilst 

 they usually give the name ' gracilis ' to the semitendinosus. 

 The ' semimembranosus ' and ( semitendinosus ' have the same 

 origin and general arrangement as in Man ; but both of them are 

 inserted into the tibia by a broad aponeurosis, extending much 



