OP THE NAILS. 227 



or middle part, is of a middling thickness; its external free 

 face is smooth, presents longitudinal furrows, more or less 

 deep, and is transversely convex. Its opposite face adheres 

 closely to the skin; the posterior part of the body of the nail, 

 for a small extent and which gradually diminishes in proceed- 

 ing from the thumb to the fourth or little finger, is white; 

 this semi-lunar portion has been called the lunula; the other 

 part appears reddish on account of its transparency, which 

 renders visible the colour of the skin. The free extremity of 

 the nail is its thickest part; it projects beyond the end of the 

 finger and shows a tendency, although but slight, to curve into 

 a sort of hook. 



329. The connexion of the nail with the dermis and epi- 

 dermis is effected in the following manner: the dermis is thick- 

 ened and very papillar beneath the body of the nail, under the 

 lunule excepted; the papillae are arranged in linear series 

 like very delicate and closely approximated longitudinal sulci. 

 The corresponding face of the nail is soft, pulpy and furnished 

 with longitudinal grooves, which receive and adhere very 

 closely to the papillary furrows of the dermis. Their separa- 

 tion, however, in the dead body, is produced by the same 

 causes that separate the epidermis and mucous body from the 

 dermis. The adhering extremity of the nail, very thin and very 

 soft, is received into the bottom of a fold of the dermis, de- 

 prived of epidermis. Under the small and irregularly deve- 

 loped nails of the last toes, the papillae of the dermis are ar- 

 ranged irregularly and not in linear series; the adhering face 

 of the nail presents the same irregular disposition for the re- 

 ception of the papillae. 



330. The epidermis having arrived near the root of the 

 nail, is reflected with the dermis to the bottom of the furrow. 

 There the dermis passes under the nail; the epidermis on the 

 contrary is reflected over its root, and is prolonged over its 

 external face, which it thus covers with a very thin lamina, 

 that is confounded with it. At the free extremity of the nail 

 the epidermis of the end of the finger is reflected under its 

 deep face and is united to the free part of that face. On the 



