DIFFERENCES BETWEEN ASSES AND HORSES. 417 



above downwards, is more or less cylindrical ; and that of 

 the horse is more or less in the form of a truncated cone. 



Fi<T. 445. — Side view of incisors of a 14 year-uld lioise (nal. size) 



Fig. 446.— Front view of incisors of a 14 year-old horse (nat. size). 



17. The teeth of the horse are more highly speciahzed 

 than those of the ass. A valuable and well-known factor 



