THE LIMBS. 197 



the lower edge of the lamallar tissue. This, like the 

 first, has a fine villous surface. The great size of 

 this region is one of the peculiarities of the horse's 

 foot. The covering of the sole is continuous pos- 

 teriorly with that of the plantar cushion, which has 

 also a villous surface. 



Over the whole of this soft, sensitive, and highly 

 vascular derm is, as before said, a very thick epider- 

 mic layer, which is distinguished by the name of 

 " hoof." One of the properties of the horny material 

 of which this is composed, which specially fits it for 

 the function it has to perform, is that it is a non- 

 conductor of heat. It is also moderately hard, tough, 

 and elastic, and, like all epidermic structures, not 

 sensitive itself, though it will transmit impressions 

 through its tissue to the sensitive structures below. 



From the foot of the dead animal the hoof may 

 be removed entire by maceration or by immersion in 

 hot water, when it will be seen to form a hollow box 

 or case of somewhat complex form, its inner surface 

 being exactly moulded on the parts around which it 

 grows. Its general shape is that of an obliquely 

 truncated cone, considerably higher in front than be- 

 hind. As in the vascular surface beneath it, several 

 distinct portions or regions can be distinguished. 

 The densest and most important part is the "wall" 

 or '" crust," which exactly corresponds to the whole 



