200 



THE SKIN 



intermediate products of chemical metamorphosis, keratohyalin 

 and eleidin, which may be considered as the predecessors of the 

 keratin which is peculiar to the cells of the horny portion. 



-a 



FIG. 179. TRANSECTION OF THE SKIN OF A HUMAN FINGER. 



a, scaly layer ; J, layer of flattened cells ; c, stratum lucidum, appearing indistinct 

 in this preparation; </, granular layer; e, germinal layer; /, papillary layer of the 

 derma; <?, reticular layer; A, subcutaneous connective tissue ; beneath *, the duct of a 

 sweat gland is seen in the middle of the epidermis. Hematein, Weigert's elastic tissue 

 stain, and picro-fuchsin. Photo, x 48. 



Granular Layer (Stratum Granulosum).In the thicker parts 

 of the cuticle the most superficial prickle cells become slightly flat- 

 tened, and coarse granules appear within their cytoplasm. These 

 cells form the granular layer (stratum granulosum), a double cell 

 layer which occupies the superficial portion of the rete mucosum. 



The cells of the granular layer are flattened and angular. 

 They possess an indistinct, apparently degenerating nucleus, and 

 their cytoplasm contains large plate-like granules of keratohyalin 

 (eleidin of Kanvier), which are strongly basophile and stain readily 

 with most nuclear dyes. 



