OSTEOLOGY. 35 



for the tendon of the flexor of the metatarsus. It has a depres- 

 sion in front for the middle patellar ligament. 



The external tuberosity, with a facet for the fibular head. 



The internal tuberosity, with ligamentous imprints. 



Above, two oval depressions for the condyles of the femur; the 

 external is the wider. Between the two an eminenpe, the spine, 

 for attachment of ligaments and cartilages. 



The inferior extremity shows 



An external tuberosity, with a vertical fissure for the lateral 

 extensor of the phalanges. 



An internal tuberostty, with an oblique channel for the oblique 

 flexor of phalanges. 



An articular surface for the astragalus, two antero-posterior 

 depressions, separated by a median elevation. 

 Articulations, 4. 



Femur, patella, fibula and astragalus. 



THE FIBULA OR PERONEUS. 



The fibula is a rudimentary bone lying outside the tibia and 

 articulating with it alone. 



It has a superior and inferior extremity and shaft. 



The superior extremity is called the head, and shows internally 

 an articular facet for the tibia, externally rough elevations for 

 ligaments. 



The inferior extremity ends in a blunt point at the end of the 

 upper third of the tibia. 



The shaft is thin and small, forming the outer side of the tibial 

 arch. 



THE PATELLA. 



The patella is a sesamoid bone, developed in the tendon of the 

 triceps extensor and strongly attached to the tibia by three liga- 

 ments. 



It has a superior face, rough, for attachment of the extensor 

 cruris. An anterior, convex, and a posterior, covered with carti- 

 lage and divided by a median ridge into an external and internal 

 articular facet, the latter the larger, and both articulating with the 

 femoral trochlea. 

 Articulations, 2. 



Femur and tibia. 



