1154 



THE ORGANS OF SPECIAL SENSE 



are being constantly rubbed off, and are being replaced by cells from the Mal- 

 pighian layer, which are converted into keratin as they approach the surface. 



The Malpighian layer (stratum Malpighii) of the epidermis is divided into 

 four layers, named, from without inward, the stratum lucidum, the stratum granu- 

 losum, the stratum mucosum, and the stratum germinativum. 



MOUTH OF 

 HAIR-FOLLICLES 



* FURROW 



r: OF SKIN 



FIG. 864. The furrows of the skin and the areas which these furrows delimit, reproduced from an impression of 



the dorsal surface of the wrist. (Toldt.) 



The stratum lucidum is the most superficial part of the Malpighian layer. It 

 consists of several layers of flat cells, the nuclei of which are beginning to disappear. 

 The cells contain eleidin granules. In regions where the epidermis is thin the 

 stratum lucidum is absent. 



The stratum granulosum consists of several layers of nucleated flat cells, con- 

 taining keratohyaline granules. These granules are probably formed from the 

 disintegrating nucleus, and in the stratum lucidum are converted into eleidin, 

 an intermediate substance in the formation of keratin. 



FURROWS OF SKIN 



TOUCH CORPUSCLE- 



i STRATUM CORNCUM 

 EPiDERMIS-j STRATUM LUCIDUM 



RETE MUCOSUM --" 



( STRATUM PAPILLARE 

 CORIUMJ 



STRATUM RETICULARE I --- JJS 



SUBCUTANEOUS 

 ARCOLAR TISSUE" 



ORIFICE OF 



SUDORIFEROUS 



DUCT 



SUDORIFEROUS 



DUCT 



CAPILLARY 

 -LOOP OF 

 PAPILL 



BLOODVESSELS 

 OF CORIUM 



BODY OF 



J^-SUDORI FERGUS 

 GLAND 



FIG. 865. Vertical section through the skin of the finger-tip. The layers of the epidermis and of the corium. 

 ihe subcutaneous areolar tissue. The sudoriferous or sweat-gland. (Toldt.) 



The mucous layer or the stratum mucosum consists of numerous layers of nucle- 

 ated, polygonal, spine-shaped cells known as prickle cells or finger cells. Between 

 the cells of the stratum mucosum are spaces containing pigment granules and 

 leukocytes. Processes from the prickle cells join adjacent cells. This layer 

 contains numerous connective-tissue fibres arranged in a network, and known as 

 epidermic fibrils. 



The stratum cylindricum or stratum germinativum is composed of cylindrical 

 or prickle cells, the points of which are directed downward. Fine fibrils pass up 



