THE PENTADACTYL TYPE. 139 



animals is wholly wanting, or is represented by a 

 mere knob on the upper extremity of the tibia. The 

 limbs of turtles and alligators possess a radius and an 

 ulna, and a tibia and fibula, all being as distinct and 

 evenly divided as corresponding bones in the limbs of 

 the human race. 



The horse is a one-toed creature; but the fossil 

 remains of its extinct predecessors show that the orig- 

 inal hippuSj or the earliest of the equine family, pos- 

 sessed five toes, and was not larger than the smallest 

 ponies now in existence. The fossil bones of a horse 

 with three toes, the central digit being the largest, are 

 found in the Eocene and Miocene beds of the Upper 

 Missouri River in the "bad lands" of Wyoming. 

 In the Pliocene strata are found the fossil bones of a 

 bigger horse, which had a large toe that reached the 

 ground, and two lateral toes that were rudimentary, 

 as are the "dew-claws" of an ox or other even-toed 

 animal. 



The horse of our time is one of the most beauti- 

 ful and highly developed of the great animals. He 

 is fleet of foot and strong of limb. Each pedal ex- 

 tremity possesses a series of toggle-joints, as the 

 articulations of the limbs may be called, consequently 

 in him is made the best provision for an outlay of 

 muscular and mechanical power. The legs are long 

 and slender, and moved by muscles which are admi- 

 rably arranged for the development of strength and 

 speed. The spinous processes of the anterior dorsal 

 vertebrae are long and high, to give an elevated at- 

 tachment to muscles which indirectly lift the feet 

 from the ground. A horse "high in the withers" is 

 riot likely to stumble when he trots. The moose is a 

 trotting animal, and has few smooth roads to travel 



