ILLUSTRATIONS 



FIG. PAGE 



Comparative view of skeletons of man and horse 



(Frontispiece) 



1. Diagrammatic representation of skeletons of the fore 



foot of perissoclactyle and artiodactyle ungulates . 15 



2. Restoration of the skeleton of Phenacodus primcevus . 21 



3. Upper molar teeth of Phenacodus, Ilyracotherium, and 



Anchitherium 31 



4. Bones of the foot of Anchitherium .... 37 



5. Bones of the foot of Hipparion 38 



6. Bones of the foot of horse 39 



7. Plantar surface of fore and hind foot of Malay tapir . 47 



8. American tapir (Tapirus americanus) .... 50 



9. Indian rhinoceros (Rhinoceros unicornis) ... 61 



10. Section of molar tooth of Hipparion .... 71 



11. African wild ass (Equus asinus) and foal ... 87 



12. Common or mountain zebra (Equus zebra) ... 91 



13. Burchell's zebra (Equus burchelli) .... 93 



14. Quagga (Equus quagga) 96 



15. Side view of skull of man . . - . . . . 107 



16. Side view of skull of horse 109 



17. Incisor tooth of Anchitherium aurelianense . . . 121 



18. Unworn crown of temporary incisor tooth of young 



horse 121 



1 



