20 



EVOLUTION OF THE HORSE 



Hypohippus small rudiments still remain representing the first 

 and fifth digits, but there is no splint of the fifth, as in Mesokippus. 

 The second and fourth digits still touch the ground, though lightly. 



A 



metastyle 



esostyle parastyle 



metacone- 



metaconule- 



hypostyk' 



hypocon&~ 



B 



^^l^gp^y 





postfoszette—* 



t ^-^ O h 



vt—prefcssette 



C (g 







crochet — 





JML-antecrochet 



D 



inetaloph 



proto/oph 



FIG. 3.— UPPER MOLAR OF MODERN HORSE, SHOWING EARLY STAGES 

 OF WEAR OF THE TOOTH. CROWN VIEW. NATURAL S'ZE 



The feet of Parahippits were much like those of Hypohippus, but 

 the side toes were smaller. 



10 and ii. Protohippus and Pliohippus. Middle and 



