i3 6 Life of Upper Lake Region. 



and a great relative diminution in the outer 

 bones, until in the modern horse we see the 

 total retirement of the second and fourth 

 metacarpals except as useless splints. This 

 change occurred between the time of the Hip- 

 parion and that of the living horse. Or, these 

 facts stated a little differently: Formerly the 

 metacarpal bones held the toes to their work, 

 and for this purpose were articulated below to 

 the phalanges or toes ; now these toes are cast 

 off and the metacarpals are only articulated 

 above. Formerly the middle or third meta- 

 carpal differed but little from the outer ones 

 in size, strength and symmetry of form; now 

 it alone can be considered, for all others are 

 rejected from their former functions except 

 this third or center bone. The rest are but 

 the useless tools of former working forces. 



PROTOHIPPUS. 



Another horse whose remains are abun- 

 dant in the Upper lake bed, is designated by 

 Paleontologists as Protohippus. As his name 

 indicates, he approaches the modern horse 



