THE SKELETON 



arm. 



The femur or thigh-bone corresponds with the humerus of the 

 In general form it resembles that bone, but is much larger 

 and stronger, having to bear the weight of 

 the body. Its upper extremity is provided 

 with a rounded head which articulates with 

 the acetabulum of the hip-bone, forming a 

 ball-and-socket joint, somewhat similar to 

 that of the upper arm, but differing in one 

 important respect. The rounded head of 

 the femur is much more prominent than 

 that of the humerus, and the acetabulum 

 is much deeper than the glenoid cavity of 

 the scapula. Thus the thigh has not the 

 freedom of motion of the humerus, but is 

 less easily dislocated. 



The calf-bones, like those of the fore- 

 arm, are two in number the tibia or 

 shin-bone, and the fibula (Lat. a clasp or 

 buckle) or splint-bone. These bones cor- 

 respond with the ulna and the radius, 

 but the fibula does not rotate round the 



Fig. 34. Right foot, 

 viewed from above. 



a, b, cd, e, f, g, and h, the 

 tarsal bones ; I to V, meta- 

 tarsal bones ; i and 3, pha- 



langes of great toe ; i, 2, 

 and 3, phalanges of second 

 toe. 



Fig. 35. The Bones of the Foot, viewed from the side, showing the 

 arched form. 



tibia as does the radius round the ulna ; it is slender throughout 

 its length, and is firmly fixed to the tibia at both ends. The 



