HORSE-BACK RIDING. 15 



ditions, by virtue of the contractile power inherent in 

 their coverings. 



The divers functions of the organs of the senses, 

 the production of the sound of the voice, that of 

 speech, necessitate also varied, and more or less com- 

 plicated movements, not only in the position of the 

 organ of the sense taken as a whole, but also in re- 

 ciprocal relations of its divers constituting parts. 



It may be said in a general way, that all the func- 

 tions of the economy are accompanied by move- 

 ments. 



