THE ANCESTRY OF THE HORSE 167 



are quite small, foreshadowing the time when 

 they shall have disappeared entirely. It may 

 also be noted here that the splint bones of the 

 horses of the bronze age are a little longer than 

 those of existing horses, and that they are 

 never united with the large central toe, while 

 nowadays there is something of a tendency for 

 the three bones to fuse into one, although part 

 of this tendency the writer believes to be due 

 to inflammation set up by the strain of the 

 pulling and hauling the animal is now called 

 upon to do. Some of these three- toed Hippo- 

 theres are not in the direct line ol ancestry of 

 the horse, but are side branches on the family 

 tree, having become so highly specialized in 

 certain directions that no further progress 

 horseward was possible. 



Backward still, and the bones we find in the 

 Miocene strata of the West, belonging to those 

 ancestors of the horse to which the name of 

 Mesohippus has been given because they are 

 midway in time and structure between the 

 horse of the past and present, tell us that 

 then all horses were small and that all had 

 three toes on a foot, while the fore feet bore 



