PELVIC LIMBS. 



81 



medial condyles (a and b] of the tibia. The 

 condyles are oval, convex dorsoventrad, and 

 concave from side to side. The two con- 

 dyles are separated at the middle of their 

 contiguous margins by a bicuspid projection, 

 the spine of the tibia (c). They are con- 

 tinuous dorsad, but separated ventrad by a 

 deep notch between the tuberosities, the 

 popliteal notch. On the distal side of the 

 lateral condyle is an elongated tacet for the 

 proximal end of the fibula. 



The shaft is triangular, smallest at about 

 its middle and enlarged at both ends. It 

 presents dorsal, medial, and lateral borders, 

 and medial, lateral, and ventral surfaces. 

 The lateral surface is concave proximad. 

 The medial surface is convex. The two 

 are continuous at the distal end. At their 

 proximal ends the border separating them 

 is raised into a prominent ridge, the crest 

 (</) of the tibia, the proximal end of which 

 contributes to increase the proximal sur- 

 face of the bone, and presents an oblong 

 tubercle (e) for the insertion of the liga- 

 mentum patellae (ligament of the quadri- 

 ceps femoris muscle). The ventral surface 

 is concave proximad where it abuts upon the 

 tuberosities. Its proximal half is crossed by 

 two rough parallel lines, the distal one of 

 which crosses in a spiral course from the 

 lateral to the medial border; near its begin- 

 ning is a nutrient foramen. 



The distal end extends farther distad on 

 its medial side. The extension is the medial 

 malleolus (/). The malleolus presents two 

 grooves on its medial surface for the tendons 

 of muscles. On the lateral side of the distal 

 end is an oblique triangular facet for the 



tt 



FIG. 57. TIBIA AND 

 FIBULA OF LEFT 

 LEG, DORSAL VIEW. 

 /, tibia; //, fibula. 

 a, medial condyle of 

 the tibia; b, lateral con- 

 dyle; <", spine of the 

 tibia; d, crest of the 

 tibia; e, tubercle for at- 

 tachment of the patellar 

 ligament; _/, medial 

 malleolus; g, projection 

 of dorsal surface of the 

 tibia; h, head of fibula; 

 i, lateral malleolus. 



distal end of the 



