388 
DARWINISM 
CHAP. 
Protoliippus 
( Hipparion ). 
MIOCENE. 
M ioh ip pus 
( Anchitherium ). 
Mesoliippus. 
EOCENE. 
Orohippus. 
Pig. 33.—Geological development of the horse tribe (Eolnppus since discovered) 
