330 



MICROSCOPIC ANA TOMY OF THE ORGANS. 



and the hard, corneous part or true nail. The Malpighian 

 layer of the nail, which consists of polygonal prickle cells, fills 

 the spaces between the furrows of the nail bed and covers it 

 with several layers of cells (Figs. 252 and 253). The Mal- 

 pighian layer of the nail under the nail root is much more 

 strongly developed, and is known as the matrix unguis (Fig. 

 250), because from this place the growth of the nail takes 



FIG. 252. 



alpighian 



(issue of 



,,i! bed 



BwMofin. 



Eponycliium 

 Nail groove. 



rpuscle 



Part of a transverse section through the terminal phalanx of the finger of a child sixteen 



days old. x 22. 



place. The matrix is conspicuous as the whiter part of the 

 nail, and ends anteriorly in a curved line, and forms the so- 

 called lunula. Here we find a stratum granulosurn, which 

 does not occur in the nail region. 



The cells of the nail itself are flat and horny, and in them 

 can be seen distinct nuclear remains. By the joining together 

 of many of such cells the so-called nail leaves are formed. 

 These overlie one another like tiles. The white areas often 

 seen in nails are due to air bubbles which collect between 

 the leaves. 



As the Malpighian layer of the nail groove passes over 

 into that of the skin in the nail wall, a stratum corneum 

 appears, which covers a part of the upper surface of the nail 

 and forms the eponychium. At the anterior border of the 



