20 EVOLUTION OF THE HORSE 
Hypohippus small rudiments still remain representing the first 
and fifth digits, but there is no splint of the fifth, asin Mesohippus. 
The secondand fourth digits still touch the ground, though lightly. 
cmesostyle 
parastyle 
metastyle 
[ py a A 
metacone-4. ae y 
er ee ga---p2racone 
metaconule-« P r | 
 hypostyller Gi Me ae 
hypocona~- 
--protoconule 
—protocone 
~-prefossette 
2) 
crochet~ 
NW 
/ = 
metdloph 
protoloph 
FIG. 3.—UPPER MOLAR OF MODERN HORSE, SHOWING EARLY STAGES 
OF WEAR OF THE TOOTH. CROWN VIEW. NATURAL SIZE 
The feet of Parahippus were much like those of Hypohippus, but 
the side toes were smaller. 
to and 11. Protohippus and Pliohippus. MippLe and 
