296 THE ANIMAL KINGDOM. 



the ruins of Nineveh by Layard ; the Horse is constantly 

 sculptured, decked in the most gorgeous trappings and 

 driven by reins and a bit, almost in the same manner 

 as in the present day, and these sculptures are among the 

 earliest records of Man's hands. There are several breeds 

 of Horses ; the chief are the Arabian (from which stock 

 proceed our race-horses), the Flanders or Cart-horse, and 

 the Sheltie or Shetland-horse. The Horse is nowhere 

 found in a state of nature, yet many wild Horses graze 

 on the plains of America, but it is known that these are 

 not native, but proceed from those placed there to 

 graze, and which have bred and run wild. The Ass is 

 distinguished from the horse by the tail having short hair 

 on it, except at the extremity, and the mane being short 

 and upright. 



7. The CETACEA, or "Whale kind, inhabit chiefly the 

 colder latitudes, they are entirely aquatic, but breathe air ; 

 the Whale, Narwal, Dolphins, and Porpoises are the chief 

 members. 



In Whales (fig. 65) the anterior extremities are so deve- 

 loped as to form a sort of fin called a " flipper," but in which 



PIG. 65 WHALE (Balena mysticetus), 



all the usual bones of an extremity exist; the posterior 

 extremities are modified so as to completely resemble the 

 tail of a fish; they have smooth skins devoid of hair. 

 AH these tribes have a considerable thickness of fat or 



