SECT. 5I.J NAILS. 97 



skiii, but tlicir terminations are unknown; I, at least, have never 

 found nerves in the lamina?. 



In the nail itself, the root, the body, and the free border may be 

 distinguished. The soft root corresponds in its extent to the 

 posterior ridged part of the bed of the nail, and is cither entirely 

 concealed in the fold, or a small semi-lunar part of it, the lunula, 

 is exposed. The posterior border is sharp, slightly bent upwards, 

 and is the thinnest and most flexible portion of the nail. The 

 hard body, which increases in thickness and breadth from behind 

 forwards, lies, for the most part, with its superior surface exposed; 

 its somewhat sharp and thin lateral edges are concealed in the 

 lateral portions of the fold, and its inferior surface is situated 

 upon the anterior segment of the bed of the nail ; lastly, the free 

 border is, in cut nails, directed straight forwards. 



Fig. -12. 



¥~~ 6 



Longitudinal section through the middle of the nail and its bed ; magnified R times, a. Bed 

 of the nail, and cutis of the hack and point of the finger; 6 mucous layer of the point of the 

 finger ; c. of the nail ; d. of the bottom of the fold of the nail ; e. of the bark of the finger ; 

 / horny layer of the point of the finger; g beginning of it under the edge of the nail; h. 

 horny layer of the hark of the finger; i. termination of it upon the root of the nail ; k. body ; 

 /. root; m. free edge of the proper substance of the nail. 



. The inferior surface of the body and of the root of the nail 

 corresponds in form exactly to the bed, and, accordingly, presents 

 lamina? and ridges with intermediate furrows; and as the elevations 

 and depressions mutually lock into each other, the nail is main- 

 tained in close connection with the cutis, and all the more inti- 

 mately, from the circumstance that the wall of the nail lies with 

 its under surface upon the lateral borders and the root. The colour 

 of the nail is, at its free border, whitish and transparent; in the 

 body, reddish ; in the lunula, whitish. When separated from the 

 epidermis and cutis, the nail is rather uniformly white and trans- 

 parent, but likewise somewhat whiter at the root than in the body. 



§ 51. St, ■uriii re of the Nail. — The nail is composed, in its deeper 

 portions, of a soft white mncous layer, which is more sharply de- 

 fined from the hard external horny layer, or proper nail, than are 

 the corresponding layers in the ordinary epidermis. The mucous 



11 



