34 



THE BOOK OF NATURE STUDY 



embedded in the sole of the human foot, answers to the " cannon " 



bone, which lies between the " hock " (ankle) and the fetlock ; 



and the bones from the fetlock to the hoof similarly answer to the 



toe of the human foot. A reference to Figs. 7 and 8 should make 



this clear. 



A comparison of the foot of the horse with that of the dog on 



the one hand, and of man on the other, will bring out yet further 



interesting facts. 



The horse, we have remarked, walks upon the tip of the third 



toe, all the other toes having vanished. The dog, however, walks 



upon the whole under sur- 

 face of the toes, which 

 are provided with swollen 

 cushions, or pads of fat 

 held in a fibrous mesh- 

 work, so as to reduce 

 jarring (Fig. 9, P). These 

 pads serve the purpose, 

 in short, of the pneumatic 

 tyres placed on wheels. 

 But what answers to the 

 palm of the hand and the 

 sole of the foot never 

 touches the ground. It 

 would seem the ancestors 

 of the horse also walked 



'Toe 



Heel 



HpcK 



FIG. 8. Bones of the foot of the horse and man 

 compared ; note that what answer to the bones of 

 the sole of the foot in man, in the horse form the 

 lower portion of the " leg." The third toe in the 

 upper figure is marked in solid black. 



upon the whole under surface of the toes, since a careful search 

 among the hair of the hind surface of the fetlock will reveal a 

 small bare surface which answers really to the foot pad of the 

 dog. A reference to the figures given herewith (Fig. 9) should 

 make this clear. This bare surface in the horse is known as the 

 " ergot." 



Yet another peculiarity of the horse's leg demands notice. 

 Every one will have noticed, on the inner aspect of the fore- 

 and hind-legs of the horse, a long, oval patch of bare skin which 

 projects from the surface of the leg for some distance, and is 

 of a hard, horny consistence. These patches are known as the 

 " chestnuts," or " callosities " of the horse. On the fore-leg these 



