THE LIMBS 



167 



ness 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 line, by 

 a mass of dense adipose tissue (the ' fatty cushion of the 

 fetlock'). On the centre or most prominent part of 

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

 hair around it is clipped off, a roundish, bare patch 

 (fig. 23, c, 6, p. 169 ; fig. 25, 19, p. 179), covered 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 peculiarly 

 modified and hairless spot of skin, with its fatty cushion 

 beneath, has ever been pointed out ; nevertheless, al- 

 though 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 fea- 

 tures 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 surface of the 

 fore limb of the horse below the so-called 4 knee '), we 

 see slight prominences just behind the root of each 

 finger and opposite the knuckles on the back of the 



