THE SKIN. 



the smooth muscles straighten, causing a projection of the 

 pilous bulbs to which they are joined. 



Fig. 93. Diagram of the skin in general.* 



The epidermis forms the essential part of the skin : it is 

 this part which first appears in the embryo, at the same time 

 with the epithelium of the digestive tube, the dermis being 

 subsequently formed and or- 

 ganized. This cellular cov- 

 ering is composed of several 

 layers of globules, the deepest 

 being columnar or cylindri- 

 cal, like those of the intesti- 

 nal mucous, and constituting 

 What is called the layer of Fig 94. -Diagrajn^the layers of the 



Malpighi (or mucous layer, 



rete or stratum mucosum) ; in the more superficial zones, the 



* Section from the scalp (Gurlt). , Epidermis. 6, Stem of a hair. 

 c, /*j g, Sudoriparous gland. ?, e?, Sebaceous gland and its excretory tube. A, t, 

 Adipose tissue. /, Bulb of the hair. 



f 1, Malpighi's layer. 2, Layer of cells whose dimensions are nearly equal 

 in all directions. 3, Superficial layer of flattened corneous cells, which have lost 

 their nuclei. 



