26 



THE BONES OF THE FOOT. 



lateral prominences already mentioned in a downward direction 

 almost as far as the lower end of the bone. The triangular 

 surface thus formed is rough for tlie insertion of ligaments. 

 The lateral surfaces of the bone are rounded and very rough 

 towards the base. 



The lower end of the bone is smooth and covered with carti- 



^i 



Fig. 12.— i'astern and sesamoideal bones 

 seen from same point as fig. 10. A, 

 pastern; />, sesamoid bones; a, npper 

 articular surface of pastern ; b, do. of 

 sesamoids; c and d, rough surfaces for 

 insertion of ligaments; e, lower arti- 

 cular surface. 



Fig. 13. —Posterior view of pastern 

 and sesamoid bones. A, pastern ;. 

 B, sesamoids ; n, rough triangle for 

 ligamentous iusei'tion : b, surface 

 for insertion of superior sesamoideau 

 ligament ; c, surface covered (in 

 lite) by intersesamoidean ligament. 



lage. Its centre presents a slight depression (tig. 12, e), and on 

 either side a prominence, the inner being somewhat larger than 

 the outer and projecting rather further backwards. Above 

 these prominences are rough surfaces for the insertion of liga- 

 ments (fig. 12, d). 



o 



O. 



The two Sesamoid Bones 

 (Figs. 10 and 11, C ; Figs. 12 and 13, B) 



Are small rounded pyramidal bones lying at the back of the 

 lower portion of the great metacarpus. They appear to con- 

 tinue the suffraii^dnis bone. Each has three surfaces, a summit 

 and a base. The anterior surface (fig. 12, h) is slightly concave, 

 almost triangular, and covered with articular cartilage. The 

 opposed borders of the two bones are so rounded off that when 

 in position they enclose a groove corresponding to and con- 

 tinuing the central groove on the upper end of the suffraginis 

 bone. The two sesamoids, combined with the suffraginis bone. 



