CH. XXXVIII.] 



THE EPIDERMIS 



575 



it is subjected to most friction. The cells of the deepest layers of 

 the Malpighian layer are columnar in shape ; the layers next to these 

 are composed of polyhedral cells, which become flatter as they 

 approach the horny layers. Between these cells are fine intercellular 



l) 



E 



passages, bridged across by fine 

 protoplasmic processes, which 

 pass from cell to cell ; the spaces 

 between the cells serve for the 

 passage of lymph. It is in the 

 cells of the Malpighian layer that pig- 

 ment granules are deposited in the 

 coloured races. 



Between the horny layer and the 

 Malpighian layer are two intermediate 

 strata, in which the transformation of 

 protoplasm into horny material (kera- 

 tin) is taking place. In the first of 

 these that is, the one next to the 

 Malpighian layer, the cells are flat- 

 tened, and filled with large granules of eleidin, an intermediate sub- 

 stance in the formation of horn. This layer is called the stratum 

 granulosum. 



Above this are several layers of clear, more rounded cells, which 

 constitute the stratum lucidum ; and above this the horny layer 



FIG. 437. Vertical section of skin. 

 A. Sebaceous gland opening 

 into hair follicle. B. Muscu- 

 lar fibres. C. Sudoriferous or 

 sweat-gland. D. Subcutaneous 

 fat. E. Fundus of hair follicle, 

 with hair papilla. (Klein.) 



