. The anatomy of the human body. Human anatomy; Anatomy. THE APPENDAGES OF THE SKIN. 637 from the finger on to the dorsal surface of the nail, as far as the curved line that marks the posterior boundary of the body of the nail; from thence it is reflected back- ward, folded upon itself, as far as the posterior bordc r «^ of the root of the nail. At this point it is again reflected forward upon itself by passing behind that border, and then (c' c') between the under surface of the nail and the dorsal aspect of the phalanx: in consequence of this two- fold reflection, it follows that it is alway
. The anatomy of the human body. Human anatomy; Anatomy. THE APPENDAGES OF THE SKIN. 637 from the finger on to the dorsal surface of the nail, as far as the curved line that marks the posterior boundary of the body of the nail; from thence it is reflected back- ward, folded upon itself, as far as the posterior bordc r «^ of the root of the nail. At this point it is again reflected forward upon itself by passing behind that border, and then (c' c') between the under surface of the nail and the dorsal aspect of the phalanx: in consequence of this two- fold reflection, it follows that it is always the epidermic S"''"' of kinonmni. surface of the true skin that is in contact with tlie nail: at the anterior extremity of the nail the skin again meets, as it were, the epidermis {a'), and becomes continuous with the integument upon the tip of the finger. But what is the arrangement of the epider- mis at the point where the skin is first reflected backward ! It is prolonged forward (a), slightly beyond the curved line formed by the reflection of the dermis, and forms a semicircular zone or band, which terminates by a smooth border, and adheres intimately to the nail. As to its arrangement beyond this point authors are not agreed. Some are of opinion that it would be prolonged upon the free surface of the nail, if it were not de- stroyed by friction ; but they overlook an objection to this view to be derived from the accustomed regularity of the epidermic border : others, again, believe that the epidermis is reflected backward like the dermis, but differ among themselves as to its ultimate dis- position ; some, for example, conceiving, with Bichat, that the epidermis is continuous with the posterior border of the nail, and some supposing that it is again reflected for- ward beneath the nail, together with the dermis (see dotted line), which, according to this hypothesis, it never quits.* A very simple experiment most clearly demonstrates the nature of the connexion
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Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
