THE EQUID^E, OR HORSES. 211 



days of a full dentition, and its disappearance 

 probably stands in causal connection with the 

 increased strength of the other teeth. 



Before discussing the American line of horses, 

 let me here quote W. Kowalewsky's opinion regard- 

 ing the connection between the genera mentioned 

 above ; his remarks are as careful as they are con- 

 vincing: * Nothing is further from my intention 

 than to maintain that the animal which we call 

 Palceotherium medium directly produced an Anchi- 

 therium, the latter an Hipparion, and so on. But 

 among the number of individuals which we call 

 Palaeotheridae, there must always have been some 

 forms which would incline more towards the Anchi- 

 therium than the others. In the same way I have 

 been able to determine owing to the large number 

 of species I was fortunate enough to be able to com- 

 pare that among the Anchitheridae a few still 

 remained completely within the limits of the species, 

 although they showed some characteristics by which 

 they resembled the Horse on the one hand, and the 

 Palaeotherium on the other. A few trifling flattenings 

 of the bones, certain peculiarities of a joint which 

 are met with in some individuals, are not to be found 

 in others. Without doubt there was at one time a 

 transition between two individuals which resembled 



