sidcnil.lc luMnlit ahovr i|„. 

 ^rournl. whciv it {^nlus tlic ln)<k 

 .i<'iiii. iM'iidiiijr hackwani, as tin- 

 kiicc hciids forward. In tln'M- as 

 in vaiious other \va\> ilu- Ic^.s ,,f 

 llic lioix' aic cspcciallN fittcrl Im 

 swill niiiniii-rovcr hard and level 

 ground, just a> its leetli are 

 fitted foi- [^nindin^ the wiiy 

 p;rasse<_ wliich <il•(,^v «,n the open 

 j)lain. 



The^zehra and the 

 ass have the same 

 })eeiiliar stnieture of 

 teeth and feet as the 

 doniestie^horse. and 

 (Hffeionly in the color 

 of the skin, ])ro|)oi-- 

 tions of various parts 

 of the l)0(lv, etc. 



FIG. 3. EVOLUTION OF THE HIND FOOT. PRINCIPAL STAGES 



(Right to Left) 1, Eohippus, Eocene Epoch 



Mciohipp !(,■<!, Oligoccno; 3, 



Merychippus, Miocene; 4, Equus, Pleistocene and Modern 



Outer views showing middle and outer digits. Note progressive reduction of 

 side toe (digit IV) from a well developed digit to a splint bone ii 



