404 



THE SKIN AND ITS APPENDAGES. 



decker) : A fresh piece of epidermis is macerated for a few hours in 

 filtered, cold-saturated, aqueous solution of dry pancreatin ; the whole 

 may then be preserved for any length of time in equal parts of glycerin, 



Outer dark layer. 



Stratum corneum. 

 Middle light layer. 



Inner dark layer. 

 Stratum lucidum. 



Stratum Malpighii. 



\ 



V 



Cutis and sub- 

 cutis. 



Fat cell. 



w , . ,-. ... 



Fig. 326. Transverse section through the human skin. Treated with osmic acid ; 

 X 30 : a, Part of the tortuous duct of a sweat-gland in the epidermis ; i>, duct of same 

 sweat-gland in the corium. 



water, and alcohol. Small pieces taken from such specimens are readily 

 teased and show both isolated and small groups of attached prickle cells. 

 The distribution of the pigment in the skin is best studied in 

 unstained sections. With a nearly closed diaphragm and under medium 

 magnification the pigment granules appear darker on raising the tube and 

 lighter upon lowering it. 



In sections of skin treated with Flemming's fluid, the structure 

 of the cutis also may be studied. The medullary sheaths of the nerve- 

 fibers and the fat appear black. In preparations stained with safranin the 

 elastic fibers are colored red and are very distinct (Stohr and O. 

 Schultze). For the orcein method according to Unna, see p. 128. 



Hair may be examined in water without further manipulation. 

 The cuticle is then seen to consist of polygonal areas, the border-lines^of 

 which correspond to the limits of the flattened cells. By slightly lower- 

 ing the objective the cortical substance comes into vieW with its indistinct 



