American Fossils "]*] 



and there is a rudimeut of that digit which answers to the little 

 finger of the human race. 



"The European pedigree of the horse stops here; in the 

 America Tertiaries, on the contrary, the series of ancestral 

 equine forms is continued into the Eocene formations. An 

 older Miocene form, called Mesohipptis, has three toes in front, 

 with a large splint-like rudiment representing the little finger; 

 and three toes behind. The radius and ulna, the tibia and 

 fibula, are distinct, and the short crowned molar teeth are 

 Anchitherioid m pattern. 



"But the most important discovery of all is the Orohippus 

 which comes from the Eocene formation, and is the oldest 

 member of the equine series yet known. Here we find four 

 complete toes on the front limb, three toes on the hind limb, a 

 well-developed ulna, a well-developed fibula, and short-crowned 

 grinders of a simple pattern. 



"Thus, thanks to these important researches, it has become 

 evident that, so far as our present knowledge extends, the his- 

 tory of the horse type is exactly and precisely that which could 

 have been predicted from a knowledge of the principles of evo- 

 lution ; and the knowledge we now possess justifies us com- 

 pletely in the anticipation that, when the still lower Eocene 

 deposits, and those which belong to the Cretaceous period have 

 yielded up their remains of ancestral equine animals, we shall 

 find, first, a form with four complete toes and a rudiment of the 

 innermost or first digit in front, with probably a rudiment of 

 the fifth digit in the hind foot ; while, in the older forms, the 

 series of digits will be more and more complete until we come 

 to the five-toed animals, in which, if the doctrine of evolution 

 is well founded, the whole series must have taken its origin." 



Just as Huxley was successful, when onl}^ the an- 

 cestry' to Miocene times was known, in predicting the 

 discov'er)' of older forms in the older Miocene and upper 

 Kocene, so his prediction of older Eocene forms carrying 

 the chain back to fiv^e-toed creatures proved correct. 

 One of the new links was indeed discovered before his 

 lecture had passed through the press, and he was able 

 to add in a footnote some details of the structure of the 



