84 CUTIS. [sect. 41. 



The stimulation of the extremities of the nerves in the most 

 external parts of the cutis takes place either directly or indirectly. 

 The former, such, for example, as is caused in a denuded part of 

 the cutis by a penetrating instrument, stimulating fluids, etc , is 

 much more intense than that effected through the medium of the 

 cuticle, as this covering serves as a protection against too strong 

 impressions, and moderates their influence according to its greater 

 or less development. Now it can be partly explained anatomically, 

 why the fineness and vividness of the sense of touch is not every- 

 where the same; less on the hairy scalp, the back, and the two 

 upper segments of the extremities, than on the face, the genitals, the 

 hand and foot, chest, and abdomen. Firstly, the epidermis is thin 

 where the sensibility is great, as upon the eyelids and the face, or 

 has, at least, a thin horny layer, as upon the penis and clitoris; 

 whilst, upon the back and extremities, it is, in part considerably 

 thicker. But this circumstance alone does not suffice to explain 

 all, as parts endowed with a thicker epidermis, such as the palm of 

 the hand and sole of the foot, are capable of fine and delicate im- 

 pressions, nay, more so than others with a thinner covering, as the 

 dorsal surfaces of the hands and feet. Another circumstance must 

 here manifestly be taken into account, namely, that the different 

 parts of the skin are not equally supplied xoith nerves. Simple 

 inspection shows, that the nerves upon the palm of the hand and 

 sole of the foot are more numerous than on the dorsal surface of 

 these organs ; upon the glans penis and clitoris, the nipple, the 

 face, they are more numerous than upon the abdomen, back, 

 thighs, etc. ; and my measurements of the sensitive roots of the 

 spinal nerves confirm this in part. Again, the number of the dis- 

 tinctly demonstrable dark-contoured nerve-fibres in the papillae and 

 superficial plexus is also connected with that of the nerves, for 

 nowhere is this more considerable than on the tips of the fingers, 

 the lips, the apex of the tongue, and the glans penis. 



E. H. Weber has endeavoured to prove, in his last excellent 

 paper on the sense of touch, that only the terminations of the 

 nerves in the skin, and not the fibres in the nervous trunks, con- 

 stitute the media of the sensations of pressure, warmth, and cold ; 

 and, therefore, thinks it probable that minute organs of touch, 

 hitherto unknown, may be present in the skin. R. Wagner be- 

 lieves, in fact, that Meissner and he have found these organs in the 

 so-called tactile bodies ; and has expressed the opinion that these 

 organs, which he believes are composed of membranes arranged 



