KEGUKGITANT VENOUS PULSE. 331 



ily emptied, and contain but little blood ; and in the other 

 the circulation is more difficult, and the vessels are moderate- 

 ly distended. The walls of the veins are thickest, and the 

 valves most numerous, in parts of the body which are habit- 

 ually dependent. The influence of gravity is exemplified in 

 the production of varicose veins in the lower extremities. 

 This disease is frequently induced by occupations which re- 

 quire constant standing ; but the exercise of walking, aiding 

 the venous circulation, as it does, by the muscular effort, has 

 no such tendency. 



