404 



THE DESCENT OF MAN. 



with scales like tne rest of the head; and of tliis wonderful 

 modification of structure the female exhibits only a rudi- 

 ment. Again, in Cliamcdeo Oivenii (fig. 3(5), from the 

 west coast of Africa, the male bears on his snout and fore- 



Pig. 35. Chamaeleo bifurcus. Upper figure, male ; lower figure, female. 



head three curious horns, of which the female has not a 

 trace. These horns consist of an excrescence of bone 

 covered with a smooth sheath, forming part of the general 

 integuments of the body, so that they are identical in 

 structure with those of a bull, goat, or other sheath-horned 

 ruminant. Although the three horns differ so much in 

 appearance from the two great prolongations of the skull 



