FEB., 1912. MAMMALS OF ILLINOIS AND WISCONSIN CORY. 17 



Hind foot of Wolf. 



Hind foot of Rabbit. 



Bear. 



Plantigrade type of foot. 



(Practically whole sole of foot 



touching the ground.) 



Fore foot of Horse. 



Hind foot of Deer. 



Fore foot of Mole 



Hind foot of Opossum. 



Panther. Horse. 



Digitigrade type of foot. 

 (Only toes touching the ground.) 



Deer. 



hoofs, which have been developed by modification and thickening 

 of the cuticle. The number of digits normally vary from i to 5 in 

 different animals. In the Deer the first is absent, the 3d and 4th 

 support functional hoofs, and the 2d and 5th appear as small, eleva- 

 ted lateral hoofs or "false hoofs." In the Horse the foot, structure 

 consists of a single digit (the 3d), the others having been lost.* 



ANATOMICAL AND PHYSIOLOGICAL CHARACTERS IN 



GENERAL. 



Having gained some slight knowledge of the bony framework, it is 

 essential that the student should know something more about their 



* Palaeontologists have been able to trace the evolution of the foot of the Horse 

 from its four-toed Eocene ancestor, showing the gradual lessening in the number of 

 digits. Prof. Cope believed the five- toed Coryphodon to represent a 'group, from 

 which all Ungulates have sprung. 



