108 



BONES OF THE LOWER LIMB. 



the neck, consists of a middle and two lateral parts. The middle part, 

 looking upwards to the tibia, is convex from before backwards, broader in 

 front than behind, with its outer margin higher and longer than the inner, 

 and curved, while the inner is straight. The inner lateral part is narrow, 

 and articulates with the internal malleolus ; the outer lateral part, much deeper, 

 articulates with the external malleolus. Inferiorly, there are two smooth 

 surfaces, which articulate with the calcaneum. The posterior of these, the 

 larger, concave from within outwards and forwards, is separated by a 

 rough depression for the interosseous ligament from the flat anterior sur- 

 face, which rests on the sustentaculum tali. The anterior margin of this 

 surface is continuous with the rounded surface of the head, which articulates 

 with the scaphoid bone. The posterior border of the bone lies behind the 

 sustentaculum tali, and, like that process, is grooved by the tendon of 

 the flexor longus pollicis. 



Fig. 101. Fig. 101. RIGHT FOOT VIEWED FROM BELOW, SHOWING 



THE PLANTAR ASPECT. ^ 



The indications are the same as in the preceding figure ; 

 the middle and external cuneiform bones are not lettered ; 

 the sesamoid bones are not represented ; they will be seen 

 in the view of the articulations of the foot. 



THE CUBOID BONE. 



This bone is situated at the outer side of the 

 foot, between the calcaneum and the fourth and 

 fifth metatarsal bones. It deviates from the cuboid 

 form and becomes rather pyramidal, by the sloping 

 of four of its surfaces towards the smaller external 

 border. The posterior cartilaginous surface articu- 

 lates with the os calcis ; the anterior surface, also 

 covered with cartilage, is divided into an internal 

 quadrilateral and an external triangular facet, ar- 

 ticulating with the fourth and fifth metatarsal 

 bones. On the internal aspect, in the middle, and 

 touching its superior border, is a smooth surface, 

 which articulates with the external cuneiform 

 bone, and behind this, in some instances, a smaller 

 surface articulating with the scaphoid, while 

 the remainder is rough for ligaments. The exter- 

 nal border presents a vertical groove, in which the 

 tendon of the peroneus longus lies ; and the inferior 

 surface is traversed obliquely near its anterior mar- 

 gin by a continuation of the same groove ; behind this there is a thick ridge, 

 which, with the rest of the inferior surface, gives attachment to the calcaneo- 

 cuboid ligaments. The superior surface, looking outwards and upwards, is 

 on the whole even, but rather rough. 



THE SCAPHOID BONE. 



The scaphoid or navicular bone is placed at the inner side of the foot 

 between the astragalus and cuneiform bones. It is short from behind 

 forwards, and broad from side to side. It presents posteriorly an articular 

 concavity for the head of the astragalus, and anteriorly a convex surface 

 divided, by two lines converging below, into three facets which articulate 



