BRUTE-MAN'S HELPLESSNESS 27 



adaptations to the horizontal attitude just men- 

 tioned, which had been acquired through long ages 

 by natural selection, this change suddenly turned 

 into injuries. 



For blood-vessels which before had run in a verti- 

 cal direction were made horizontal, and vice versa. 

 The valves in them, therefore, which before the 

 change had aided circulation thereafter tended to 

 congestion. 



The bones, ligaments, tendons, muscles, which 

 in the horizontal position of the body had screened 

 and protected the vital parts, thereafter exposed 

 them. The bones, ligaments, muscles, which in the 

 horizontal had firmly supported the viscera, repro- 

 ductive organs, etc., thereafter left them loosely 

 dependent, unsupported, liable to shocks, lesions, 

 and breaks. 



This is the manner in which the erect posture pro- 

 duced the helpless condition of our brute ancestors. 



