MUSCLES OF THE POSTERIOR LIMBS. 235 



cavity. It terminates, by its inferior extremity, on the anterior face of the 

 patella. 



Relations. Externally, internally, and posteriorly, with the two other 

 portions of the triceps ; anteriorly, with the muscle of the fascia lata. Its 

 superior extremity, included between the iliacus and the deep gluteus, is 

 separated from the coxo-femoral capsule by a little adipose cushion which is 

 insinuated between its two branches. 



Action. An extensor of the leg and flexor of the thigh. 



B. EXTERNAL VASTUS (Fig. 129, 4). FormExtent Situation. This 

 is a thick and wide muscular mass, flattened on each side, extending from 

 the superior extremity of the femur to the patella, and situated to the 

 outer side of the anterior rectus. 



Structure and Attachments. The fasciculi composing this muscle are 

 intermixed with strong aponeurotic layers, and originate from the whole 

 outer surface of the femur and the external half of its anterior face ; they 

 are directed forwards and downwards, to terminate either on the anterior 

 rectus, or on the superior face and external side of the patella. 



Relations. Outwardly, with the fascia lata and superficial gluteus; 

 inwardly, with the anterior rectus and the vastus internus, which is inti- 

 mately confounded with it except towards the superior extremity of the 

 femur, where the two muscles are distinctly separate; behind, with the 

 femur and the long vastus. 



Action. It is an extensor of the leg. 



C. VASTUS INTERNUS (Figs. 131, 7 ; 137, 17). This muscle is not very 

 distinct from the preceding for the greater part of its extent, and forms with 

 it a deep and wide channel, in which the anterior rectus is lodged. It is a 

 repetition of the vastus externus in so far as its form, structure, extent, 

 attachments, and action are concerned; but it possesses the following 

 peculiarities : 



The fibres entering into its composition arise from the whole internal 

 face and the inner half of the anterior face of the femur, and go to be 

 inserted, some on the aponeurosis of the rectus, others on the internal 

 patellar ligament, the corresponding side of the patella, and on the superior 

 face of the same bone, in common with the vastus externus. 



Relations. By its external face, it responds to the latter muscle and 

 the rectus ; by its internal face, to the internal crural aponeurosis, the long 

 adductor of the leg, the iliacus, pectineus, and to the long branch of the 

 great adductor of the thigh. 



3. Anterior Gracilis. (Figs. 90, 11 ; 131, 6.) 



Synonyms. Gracilis anterius Bigot. Ilio-femoral gracilis Girard. (Crureus vel 

 cruralis Percivall.) 



A small cylindrical muscle, situated in front of the capsule of the coxo- 

 femoral articulation, alongside the fibrous fasciculus that strengthens the 

 anterior portion of this membranous ligament. 



Attachments. It originates from the ilium, very near, and to the outside 

 of, the external branch of the anterior rectus ; it afterwards insinuates itself 

 between the two vasti, and terminates on the anterior aspect of the femur 

 by aponeurotic fasciculi. 



Relations. This muscle is included between the three portions of the 

 triceps and the capsular ligament of the coxo-femoral articulation, to which 

 it strongly adheres. 



