184 THE STEUCTUEE OF THE HOESE 



centre of the under surface of the toe at the apex of 

 the plantar cushion or frog. This part of the hoof- 

 matrix (fig. 25, 13), which from its structure is called 

 the i podophyllous ' or ' laminal ' tissue, is deeper from 

 above downwards in front, and gradually gets shallower 

 posteriorly, the incurved ends (which correspond to the 

 c bars ' of the horny hoof) thinning almost to nothing 

 at their terminations. Instead of being covered with 

 irregularly scattered-villi, like the coronary cushion and 

 frog, its surface is raised into very numerous (five or six 

 hundred altogether) longitudinal, parallel, fine leaf-like 

 ridges or c lamellae,' all extremely vascular and sensi- 

 tive, and being themselves covered on each side with 

 numerous other finer ridges, set obliquely upon them — 

 a most complex and delicate apparatus, enormously 

 increasing the superficial area of the keratogenous mem- 

 brane. This region of the matrix of the horse's hoof 

 corresponds to the flat surface below the human nail, 

 and the longitudinal ridges observed in the latter 

 are obviously the same structures as the lamellae of the 

 horse's foot, only in a very slightly developed condition. 



3. The third part of the matrix of the hoof is that 

 portion of the vascular derm which covers the lower 

 surface of the pedal bone, or the c sole ' of the foot. It 

 is crescentic in shape, and bordered all round by the 

 lower edge of the lamellar tissue. This, like the first, 

 has a fine villous surface. The great size of this region 



