THE HORSE. 8l 



epoch, much as the tapir wades and paddles in 

 the South American swamps at the present day. 

 During later periods there were huge herds of 

 three-toed horses abounding all the world over, 

 but, as time went on, certain evolutionary forces 

 caused the two outer toes to disappear. At 

 present, with the exception of a few curious 

 reverting " freaks " occasionally exhibited in 

 museums, all horses walk on the limb which 

 corresponds anatomically to the human middle 

 finger. The "ring" and "index" digits which 

 did duty as locomotive auxiliaries in the three- 

 toed horses have been found useless and have 

 been suppressed, although they occasionally make 

 themselves remembered in an unpleasant manner 

 even in the present day when they give rise to 

 "splints" in young horses which have been over- 

 worked. One rule of equine evolution seems to 

 have been, " the fewer the toes, the better the 

 horse." It is quite certain that a single-hoofed 

 extremity is better adapted for habitual swift 

 locomotion over hard ground than one of the 

 splay-footed type like those of the horse's re- 

 latives, the tapir and the rhinoceros. 



At present it is by no means easy to state how 

 the structural changes in the equine foot came 



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