668 AFRICAN GAME ANIMALS 



In size the sexes are very similar, the male exceeding the 

 female but little. The only appreciable secondary sexual 

 characters are found in the size of the horn bases, the nasal 

 bones which support them, and the general massiveness of 

 the skull. The base of the front horn in the male is always 

 greater than in the female, this dimension showing no rela- 

 tionship to the length of the structure. The width of the 

 nasal boss which supports the front horn is correspondingly 

 greater in the male. Male skulls are usually actually wider 

 than those of females and are always relatively so as well as 

 being longer. So marked are these sexual characters in 

 the skulls that they can be sexed with a fair amount of 

 certainty. 



The species is normally two-horned, the front horn 

 greatly exceeding the rear one in size. The front horn is 

 situated on a prominent bony boss at the tip of the nasal 

 bones and is immediately followed by the rear horn which 

 is much compressed laterally and placed on the suture 

 between the nasal and frontal bones. The front horn is 

 squared in front where it partakes of the shape of the snout, 

 and is normally curved backward as in the black rhinoceros. 

 The usual length of this horn is two feet although occa- 

 sional specimens attain a length of five feet. The record 

 horn for the South African race is sixty-two and one-half 

 inches. Such enlarged horns are attained only by the fe- 

 males in which they project forward in advance of the snout. 

 The rear horn is usually low, sharply conical, and con- 

 siderably compressed. It seldom exceeds more than a few 

 inches in height and is occasionally wanting. , The rear 

 horn never approaches the front one in size as in the keitloa 

 variety of the black rhinoceros in which the two horns are 

 equal in size. The rear horn is so small that it is obviously 

 disappearing, the species showing a marked tendency to 

 become single-horned; but actual single-horned specimens 

 are rare. 



The only parts of the body which show a growth of hair 

 are the terminal margins of the ears and the apical one- 

 fourth of the tail. The hair of the ears is quite soft and an 

 inch or so in length. The hair covering of the tail is stiff 

 and bristly, and confined to a streak along both edges of 

 the flattened tip. In the two male skins the hair covering 



