36 STRUCTURE OF THE TRUE SKIN. 



tains. Its looser internal surface, which is united 

 to the cellular membrane in which the fat is de- 

 posited, presents a great number of cells or cavities, 

 which penetrate obliquely into the substance, and 

 towards the external surface, of the skin, and also 

 contain fatty matter. These areolae or cells are 

 larger on some parts of the body than on others : 

 they are very small on the back of the hand and 

 foot, the forehead, and other places where fat is 

 never deposited and the skin is very thin; while 

 they are large in the palm of the hand and sole of 

 the foot, where the skin is consequently thicker and 

 fat abounds. These cells are traversed by innumer- 

 able blood-vessels and filaments of nerves, which 

 pass through to be ramified on the outer surface of 

 the skin, where they show themselves in the form 

 of numerous small papillae or points, which are very 

 visible on the surface of the tongue, and on the 

 fingers and palm of the hand. These papillae con- 

 stitute the true organs of touch and sensation, and 

 are therefore most thickly planted where these 

 senses are most acute. 



The true skin is so abundantly supplied with blood 

 and nervous power, that, for practical purposes, it 

 may almost be regarded as composed of vessels and 

 nerves alone ; and it is important to notice this fact. 

 The universal and equal redness of the skin in blush- 

 ing is itself a proof of great vascularity ; but a still 

 stronger consists in our being unable to direct the 

 point of the finest needle into any spot without 

 puncturing a vessel and drawing blood. The same 

 test proves the equal abundance of nervous filaments 

 in the skin, for not a point can be punctured without 

 transfixing a nerve and causing pain ; and it is well 

 known, that in surgical operations and accidental 

 wounds, the chief pain is always in the skin, be- 

 cause it is profusely supplied with nerves on pur- 

 pose to serve as the instrument of feeling. From 

 these examples, the skin may be truly considered as 



