131 



SPECIAL HISTOLOGY. 



epidermic or horny plates 

 Fig. 56. 



/ k 



/ 



They (fig. 56. 1, 2, 3) are, in fact, 

 plates of moderate thickness, which 

 in the lower and middle parts of the 

 horny layer retain tolerably regular 

 polygonal (4-5-6 sided) and smooth 

 surfaces ; in the upper layers, on the 

 other hand, they present more irre- 

 gular outlines, are variously crooked 

 and curved, and thence often appear 

 to be wrinkled and folded. These 

 plates must be regarded as cells, 

 completely flattened, and containing 

 a very minute quantity of viscid 

 fluid ; and not, as might at first be 

 imagined, as homogeneous lamellae, 

 composed throughout of the same 

 substance ; for by the addition of 

 various reagents, especially of acetic 

 acid and of potass, they swell up 

 and assume the form of vesicles (fig. 

 57) ; at the same time, a rudimen- 

 tary nucleus becomes obvious in a 

 few, particularly in those from the 

 middle and inner layers, but by no 

 means in the majority of them, in 

 the form of a flat, homogeneous, 

 rounded or elongated corpuscle, 0003 

 — 0004'" in length, and 0002—0003'" in breadth, which, 

 especially when seen from the side, is easily recognised 

 by the dark contours which it then presents. The size of 

 the plates of the ordinary horny layer varies from 0"008 — 

 0016", and in the outer layer it is commonly somewhat 

 greater than in the inner. Upon the body of the penis the 

 cells measure 0-008'" — 0012'" ; upon the glans, the largest are 

 0016 — 0-02'"; upon the outer side of the labia minora 012 — 

 002"'; on the labia majora 01 — 0016'". These last, larger 



Fig. 56. Horny plates of man, x 350 : 1, without addition, viewed from the surface 

 one with a nucleus; 2, from the side; 3, treated with water, granular and dark; 

 4, nucleated plate, such as occur on the outei surface of the labia minora and on the 

 glans penis. 



