178 THE STRUCTURE OF THE HOESE. 



tuft or lock, which has given the name of ''fetlock" 

 (i.e., foot or feet lock) to this part of the horse's limb. 

 The amount and coarseness of this growth of hair 

 varies much with the breed of the animal. The 

 prominence itself is formed partly by the sesamoid 

 bones, but also, in the middle hue, by a mass of 

 dense adipose tissue (the "fatty cushion of the fet- 

 lock"). On the center or most prominent part of 

 this can be seen, on both fore and hind limbs, when 

 the hail' around it is clipped off, a roundish, bare 

 patch (Fig. 23, C, b, p. 179 j Fig. 25, 19, p. 191), cov- 

 ered with a rough, thickened epidermis, called in 

 French veterinary works the ergot, as sometimes the 

 epidermis accumulates on it to such an extent as to 

 produce an appearance comparable to a spur. 



The area of this bare patch is relatively larger in 

 the ass than in the horse. 



I am not aware that the significance of this pe- 

 cidiarly modified and hairless spot of skin, with its 

 fatty cushion beneath, has ever been pointed out ; 

 nevertheless, although generally not noticed at all, 

 or dismissed in a few words, in all works on horse 

 anatomy, it is, when properly understood, one of the 

 most interesting features of the external and visible 

 structures of the animal's body. 



If we look at the palm of our own hand (which, 

 as shown before, corresponds with the hinder sur- 



