OF THE GLANDS OF THE SKIN. 



221 



Fig. 



84. 



these three forms, which represent only the chief varieties, 

 there are a good many intermediate 

 ones, -which do not require any de- 

 tailed description. 



The sebaceous glands occur prin- 

 cipally in the hairy parts of the body, 

 opening, in common with the hair- 

 sacs, upon the surface, whence they 

 have also been termed the (/lands of 

 the hair-sacs. 



In all the coarser hairs, the glands 

 appear to be lateral appendages of the 

 hair-sacs, and open by narrow excre- 

 tory ducts into them (figs. 75, 76, 77, 

 83), whilst in the lanugo the ducts 

 and the hair-sacs are often of about 

 the same diameter (fig. 84 B), and 

 open into a common canal, which 

 may be regarded as a continuation of 

 the one as much as of the other ; or 

 the ducts may even be the larger 

 (fig. 85), the hairs bearing a subordi- 

 nate relation to them, so that their 

 sacs open into the glands, and the d 

 hairs come out through the glandular 

 opening itself. In the hair-less parts 

 of the surface, sebaceous glands occur 

 only in the labia minora {vide § 54), 

 and in the glans penis and prepuce, 

 whilst they do not exist in the glans 

 and prepuce of the clitoris. In general, the glands are situated 

 close to the hair-sacs in the superficial layer of the corium, and 

 are larger in the finer hairs than in the coarser; in particular 

 cases, however, they present many differences. With respect 

 to the glands of the larger hair-sacs, they are usually of the 



v i^ 



Fig. 84. Sebaceous glands from the nose, x 50 : A, simple tubular gland without 

 any hair; B, compound gland, which has a common opening, with a hair-sac : 

 a, glandular epithelium, connected with b, the stratum Malpighii of the epidermis ,• 

 c, contents of the glands, sebaceous cells, and free fat ; d, the separate racemes of 

 the compound gland; e, hair-sacs (root-sheath), with the hair,/". 



