THE SKIN. 



207 



The sebaceous glands can best be described in connection with 

 the hairs and their follicles. 



The bulbous attachment, or " root," of the hair, and the adjacent 

 portion of its shaft, are contained in an invagination of the corium 

 and epidermis, called the "hair-follicle" (Fig. 181,/). This is sur- 

 rounded by fibrous tissue, forming its external coat, which may be 

 imperfectly distinguished into an outer layer, containing relatively 

 abundant longitudinal fibres, and an inner layer, in which encircling 



Fig. 184. 



Muscle cells in, a diagonally 

 cut tubule 



Gland celL 



Muscle cells 



Forked 

 muscle cell 



Muscle cells 



Nucleus of 

 gland cell 





■p — - Y ® Jj[ 



Basal 



membrane- 



Duct 



Fat cell 

 colored 

 by osmic 

 acid 



Some tubules of sweat-glands from the skin of a human finger. To the left of the two lower 

 fat-cells are muscle-fibres and a few gland-cells belonging to a tangential section of a 

 sweat-gland tubule. (X 350.) 



fibres predominate. At the bottom of the follicle this fibrous tissue 

 becomes continuous with that of a vascularized papilla, similar to 

 those existing on the surface of the corium, which projects into the 

 root of the hair. 



The fibrous sac constituting the outer part of the hair-follicle is 

 lined with a continuation of the epidermis, leaving a cylindrical 

 cavity occupied by the hair. This layer of epithelium is reflected 



