224 SKIN, HAIR, AND NAILS, BY ALFRED BIESIADECKI. 



immediately adjacent to the bloodvessels, though often also at a 

 considerable distance from them. The number and size of the 

 cells vary in different individuals, and appear to stand in 

 relation to the succulency of the skin. In young persons their 

 number and size are equal to those of the cornea, the forms of 

 which, after treatment with solution of chloride of gold, are 

 similarly liable to variation. 



The papillcB of the skin are divided into the vascular and 

 the nervous papillae. Medullated nerve fibres are always present 

 in the latter, passing to the bodies called tactile corpuscles by 

 Meissner. The former only contain vascular loops. 



The size and number of the papillae vary considerably in 

 different parts of the skin. They are most developed on the 

 palmar surface of the hand and fingers, where they form obtuse 

 cones with circular bases, and are arranged in a double series 

 along the above-mentioned striae. Their length in this part 

 amounts to O'l O2 of a millimeter, and they are either almost 

 in contact at their bases, or are separated by only' a small 

 distance, whilst in other regions they scarcely attain half this 

 height, and only form slight elevations of the surface. They 

 often coalesce at their bases, and then form compound papillae. 

 The thickness of the whole dermis is not less variable. It 

 not only presents differences in thickness in various parts of 

 the skin, but it varies also in different individuals of one and 

 the same race. According to Krause, the thickness of the der- 

 mis, which, on account of the gradual transition of the corium 

 into the subcutaneous connective tissue, can only be approxima- 

 tively estimated, amounts in the eyelid and prepuce to 0'56 

 of a millimeter ; on the glans penis, to O27 of a millimeter; 

 upon the face, on the penis, and on the area around the nipple, 

 to 0'76 1'12 ; on the forehead, to 1'52; on most other parts 

 of the body, to 1*69 2'25 ; and on the back, the sole of the 

 foot, and palm of the hand, to 2'25 2'28 of a millimeter. 



BLOODVESSELS OF THE CORIUM. 



The vascular trunks passing obliquely upwards through the 

 subcutaneous connective tissue to the corium, after having 

 first given off branches to the fat lobules, the ducts of the sudo- 



