THE CUNEIFORM BONES. 



427 



highest part of the bone, but almost the whole of this surface is on the inner side of 

 the foot. Its outer border runs obliquely forward and outward with a sinuous 

 course till it reaches the end of the middle cuneiform, when it turns forward. It 

 has a short concave posterior border for the sqaphoid and a long, nearly straight 

 one for the first metatarsal bone. It passes without a sharp boundary into the 

 lower surface. It is crossed by a faint groove, which exceptionally is deep, running 

 obliquely downward and forward to a smooth swelling for a bursa under the tendon 



Mid. cuneiform 



Scaphoid 



Fig. 441. 



Dorsal 



Second 

 metatarsal 



First 

 metatarsal 



Fig. 442. 



Dorsal 



Facet for 

 tibialis aiUicus 



Groove for 

 tendon of 

 tibialis 

 amicus 



Right internal cuneiform, outer aspect. 



Right internal cuneiform, inner aspect. 



of the tibialis anticus just before its insertion. The inferior surface, rough and 

 round, has a tubercle near the proximal end for a part of the tibialis posticus. The 

 external surface is mosdy rough, with a smooth articular strip for the middle 

 cuneiform following its upper and posterior border. The internal cuneiform articu- 

 lates with the scaphoid, middle cuneiform, and first and second metatarsal bones. 



Development. — A centre appears in the third year. Very exceptionally it is 

 double, and the bone is divided by a suture into two, — a dorsal and a plantar, 



THE MIDDLE CUNEIFORM. 



The middle cuneiform ' has a sharp ridge below and an oblong surface above. 

 The latter, or superior surface, is very little longer than broad. The lateral 

 borders of this surface have an outward inclination. The inner of them corresponds 

 to the proximal part of the outer border of the first cuneiform. The outer border, 

 for its proximal two-thirds, rests against the external cuneiform, beyond which there 

 is a small space between the bones. The proximal side of this surface is a little 

 convex and the distal ab6ut straight. The posterior surface, wholly articular, 



Fig. 443. 



Second 

 metatarsal 



Internal 

 cuneiform 



Scaphoid 



External 

 cuneiform 



Right middle cuneiform. A, inner aspect ; B, outer aspect. 



is slightly concave. It is triangular, with the dorsal border rounded, the outer 

 concave, and the inner straight or slightly convex. The anterior surface, ar- 

 ticular for the second metatarsal, is narrower. It has a slight convexity in the upper 

 part in a vertical plane. The internal surface has an articular facet corresponding 

 to that on the internal cuneiform and a rough depression for an interosseous liga- 

 ment. The external surface has a facet along the hind border, broader above 

 than below, and rarely a small one at the front lower angle, both for the external 



^ Os cuneiforrae ^cundum. 



