DISEASES OF THE FEET AND LEGS. 119 



sliding over the navicular bone (/), its termination or 

 insertion into the bottom of the coffin-bone (i-), the 

 elastic matter of the sensible frog (//), the insensible or 

 horny frog (^), the horny sole (A*), which includes the 

 parts of the sensible foot ; the outer wall of the hoof 

 (/), the elastic processes {m\ the attachment of the 

 extensor tendon to the coffin-bone {n), and its attach- 

 ment to the coronary bone {o), which completes the 

 section. 



" The coffin-bone (a) adapts itself to the figure of the 

 hoof, or rather is adapted by nature to this eligible 

 form. The eminence in its front receives the insertion 

 of the tendon of the great extensor muscle of the foot. 

 This important muscle has its upper attachment to the 

 humerus or arm-bone, where it is princij^ally fleshy; 

 but as it passes downwards it becomes tendinous, ex- 

 panding over every joint, both to prevent friction, and 

 to embrace and give firm attachment to each bone with 

 its opposed bone, by which a firm connection of the 

 various parts is maintained, and a simultaneous move- 

 ment of the whole limb is effected. In the hinder 

 limb this extensor tendon and its two less or tendinous 

 adjuncts arise from the tibia, and in part from the 

 femur, but in their origin are fleshy. 



" In the sides of the coffin-bone are attached lateral 

 cartilages, and around its surface are marks of the 

 attachment of the laminated substance. 



" The coronary, or small pastern bone (c), is seen to 

 rest on the coffin-bone («), with which it articulates by 

 its lower end ; its posterior part also may be seen to 

 be closely articulated both with the coffin and with the 

 navicular or nut bones (/), whose attachments to them 

 are effected by ligaments of great power and some 



