84 NATURAL HISTORY. 
148. There is but one known species of the Hippopot- 
amus (imroc, hippos, horse; rorapoc, potamos, river), or 
river-horse, an inhabitant of Africa. It passes a large 
portion of its time in the water, especially in the day- 
time, leaving it at night in search of its food, which is _ 
the herbage growing on the banks of rivers and lakes. 
Its hide is of great thickness, even to two inches, on its 
back and sides, and is made into shields, whips, and 
walking-sticks. This animal is supposed by some to be 
the Behemoth of the Bible. 
144. There are certain birds, called Rhinoceros Birds, 
which are always in attendance on the hippopotamus 
and the rhinoceros. They live on the ticks and other 
parasites which swarm upon these animals. It is said 
that these birds are the best friends which those huge 
creatures have, for they rouse them from their sleep 
when they see an enemy approach. 
145. The Horse Family includes the Horse, the Ass, 
the Zebras, etc. The hoof in this family is one solid 
piece, and so the family is sometimes called solidungula. 
146. The first mention made of the Horse in the Bible 
is In connection with the sale of corn in Egypt by Joseph, 
Genesis, xlvii., 17. What is the original country ofahe 
horse is not known. The herds running wild in Tartary, 
Carpenter says, are undoubtedly descendants of horses 
that have been domesticated, for their habits are the 
same with those of the herds in the pampas of South 
America, and these are known to have descended from 
horses introduced by the Spaniards. The herd has al- 
ways a leader which is a male, and when attacked they 
put the colts and the females in the rear, and make re- 
sistance by kicking with their hind feet. The natives 
catch these wild horses with the lasso, a noose of leather, 
which they throw with great skill, and they very readily 
tame them. There are herds of wild oxen as well as 
horses in the pampas of South America, and there is ac- 
cordingly an immense trade in the hides of both. 
