DETERMINATION OF RIGHT AND LEFT. 151 



arthral facet down, the cotyloid fossa looking to one side ; the fossa 

 will be on the side to which the bone belongs. 



376. Femur (Fig. 30). The bone should be placed with the 

 head pointing away from the observer, the intercondylar fossa or 

 notch down. 



The nearly spherical arthral head is situated at the proximal 

 extremity ; it faces approximately cephalad. The longitudinal con- 

 cavity of the whole bone and the intercondylar fossa or notch are 

 on the ventral aspect. 



377. Tibia (Fig. 30). It should be held with the tuberosity 

 for the patellar ligament up, the malleolus facing away from the ob- 

 server ; the end bearing the malleolus will point to the side to 

 which the bone belongs. 



The most distal part (malleolus) is on the cephalic, and the lon- 

 gitudinal concavity on the ventral aspect. 



378. Fibula (Fig. 30). If the bone be placed horizontally, 

 with its distal extremity toward the observer, and the distal arthral 

 surface up, then the deep rough depression at the latero-distal mar- 

 gin of the arthral surface will be on the side to which the bone be- 

 longs ; or, in grasping tins end with the pollex and index, the pollex 

 of the side to which the bone belongs may be easily put into this 

 depression. 



This method, so far as we know, was first devised by Gr. S. Shep- 

 pard, a student in the anatomical laboratory of Cornell University. 



The distal arthral surface is on the cephalic aspect, and the 

 depression for the ligament spoken of below is at the ventro-distal 

 edge of this surface. 



The arthral surface of the distal extremity is on the side, while 

 that of the proximal extremity is nearly on the end. The depres- 

 sion spoken of at the distal end is for the attachment of the " pos- 

 terior fasciculus of the external lateral ligament" of the ankle. 



379. Determination of the Right and Left with the Entire 

 Limbs. The sides of the whole arm may be recognized by remem- 

 bering that the capitellum, radius and pollex (thumb) are on the 

 cephalic side, while the olecranon process and fossa are on the 

 dorsal side, and the convexity of the elbow points dorsad. 



The sides of the whole leg may be determined, since the tibia and 

 primus (great toe) are on the cephalic aspect, and the convexity of 

 the knee faces dorsad. 



