PELVIC LIMBS 



737 



FIG. 557. 



The external surface is narrow above and wide below. In its 

 upper third it is slightly convex transversely, but below this area it is 

 concave down to the lower third, which is flat. The surface faces out- 

 ward above, and outward and backward below ; to it are attached the 

 peroneus longus and peroneus brevis muscles. 



The anterior surface is much narrower than 

 the external, especially above, where it does not 

 begin until the anterior-external and anterior- 

 internal borders begin to diverge. It is grooved 

 longitudinally, and affords attachment to the ex- 

 tensor longus digitorum, peroneus tertius, and 

 extensor proprius hallucis muscles. 



The internal surface is between the anterior- 

 internal and posterior-internal borders ; it is 

 narrow above and below, and grooved to give 

 origin to the tibialis posticus muscle. 



The posterior surface is between the posterior- 

 internal and posterior-external borders. It is a 

 wide surface, wider, however, below. It is so 

 twisted that, while it faces backward above, it 

 faces backward and inward in the middle and 

 directly inward below. To its roughened upper 

 part is attached the soleus muscle ; from the rest 



of the surface down to a roughened oblique line 4 - surfaceocc "Pied by the pop- 

 for a ligament at the lower end arises the flexor 

 longus hallucis muscle. 



The lower extremity is more simple than in 

 the cat; its general shape is pyramidal. Its ex- 

 ternal (anterior-external) surface is separated exte almalleo1 -: 14 . 

 from the posterior (posterior-external) surface by the oblique branch 

 of the anterior-external border of the shaft. It is not obliquely 

 grooved for tendons, nor has it the terminal posterior-inferior hook. 



The internal surface presents a triangular facet for the astragalus, 

 below and behind which is a deep depression for the external lateral 

 ligament. 



The posterior surface, sometimes called the posterior border, is 

 broad, and slightly concave for the passage of the tendons of the 

 peroneus longus and peroneus brevis muscles. 



47 



RIGHT FIBULA AND TIBIA, 

 POSTERIOR VIEW. 



1, 2, articular surfaces of the 

 tibia for the condyles of the 

 femur, separated by the tibial 

 spine ; 3, the inner tuberosity; 



liteal muscle, defined by the 

 popliteal line, 5; 6, nutrient 

 foramen; 7, surface covered 

 by the flexors of the toes; 8, 

 internal malleolus; 9, grooves 

 for tendons; 10, interosseous 

 ridge; 11, head of the fibula; 



