THE SILENT LANGUAGE OF ANIMALS 185 



the body. Nature is seldom contented with the 

 one primary function which an organ or tissue 

 performs, but adjusts and adapts it to others in 

 many ingenious ways. Hence, when an animal 

 perspires, the pores of the skin allow the con- 

 tained moisture to escape and moisten the sur- 

 face of the body ; but in addition to this, in many 

 animals, collections of these pores in the shape 

 of large glands secrete various odours which serve 

 important uses. In the skunk such a gland is a 

 practically perfect protection against attacks 

 from his enemies. He never hurries and seems 

 not to know what fear is — a single wave of his 

 conspicuous danger signal is sufficient to clear 

 his path. 



In certain species of the rhinoceros there are 

 large glands in the foot. These animals live 

 among grass and herbage which they brush 

 against as they walk, and thus " blaze' ' a plain 

 trail for the mate or young to follow. There are 

 few if any animals which care to face a rhinoc- 

 eros, so the scent is incidentally useful to other 

 creatures as a warning. 



It is believed that the hard callosities on the 

 legs of horses are the remains of glands which 

 were once upon a time useful to their owners ; and 

 it is said that if a paring from one of these hard, 

 horny structures be held to the nose of a horse, he 

 will follow it about, hinting, perhaps, that in 



