The Foot. 857 



The internal one we speak of as ' the sensitive foot/ the 

 external cover as ' the horny foot.' 



The physiological interest in the sensitive foot lies in the 

 arrangement of its bloodvessels, the provision which exists 

 for saving the parts from destruction by concussion, the 

 means by which the weight ofHhe body is supported, and 

 the remarkable manner in which the area of the foot is 

 increased without adding to its surface. 



Vascular Mechanism. — Taking the bloodvessel arrange- 

 ment, we recognise that the enormous amount of blood 

 sent to the foot is for the purpose of growing the needful 

 quantity of horn. There is hardly an}^ other part of the 

 body so vascular; even the bone of the foot is a rarified 

 structure, like so much pumice-stone, to afford passage and 

 protection to the vessels. 



Lying as the foot does furthest from the heart, added 

 to which is its position at the lowermost part of the body, 

 we are led to inquire why it is that the blood is able to 

 circulate through it so thoroughly, and if other means are 

 at hand for assisting the force of the heart in facilitating 

 the circulation : such means, we know, do exist. The 

 arterial blood pressure in the foot is high, for we have 

 gravity assisting the action of the heart and powerful 

 elastic walls to the vessels. But though the contraction of 

 the left ventricle is sufficient to bring the blood back to the 

 right side of the heart from any part of the body (as we 

 have pointed out in dealing with the circulation), it is 

 doubtful whether this would be wholly sufficient to empty 

 the foot of blood and keep the considerable plexus of veins 

 full. 



The venous circulation is assisted by two movements in 

 the foot, viz., the expansion and contraction of its posterior 

 half, and the descent and elevation of the inner foot under 

 the pressure of the body. 



There is no point in the physiology of the foot which 

 has given rise to greater controversy than its elasticity ; but 

 we submit that it is not only anatomically provided for, but 

 amply proved within recent years. Its provision exists in 



