SEBACEOUS FOLLICLES. [ 685 ] SEBACEOUS FOLLICLES. 



generally in the skin, and secrete a fatty 

 matter. They are mostly seated close to 

 the hair-follicles, into which their ducts 

 usually open. They vary in form, some 



Fig. 635. 



Simple sebaceous follicle, from the nose, a, glandular 

 epithelium, continuous with b, the rete mucpsum ; c, 

 contents of the gland, consisting of cells containing fat, 

 with free fatty matter. 



Magnified ."0 diameters. 



Fig. 636. 



Glandular vesicle of a sebaceous gland, a, epithelium' 

 ontinuous with the glandular cells b, containing fat. 



Magnified 250 diameters. 



Fig. 637. 



Cells rom the glandular vesicles and the sebaceous 

 secretion, o, small nucleated cell, containing but little 

 fat, and resembling an epithelial cell ; 6, cells abounding 

 in fat, without evident nuclei ; c, cell in which the fat- 

 globules are becoming confluent; d, cell containing a 

 single drop of fat ; e,f, cells from which part of the fat 

 has escaped. 



Magnified 350 diameters. 



being simple pouches or depressions of the 

 skin, whilst in others the deeper part of the 

 pouch is branched, so as to constitute a true 

 racemose gland. The narrower portion, or 

 duct, is variable in diameter ; it usually 

 opens into the hair-follicle, rather above its 

 middle, but sometimes upon the surface of 

 the skin itself. 



Each gland consists of an outer coat of 

 connective tissue, forming a more or less 

 thick membrane in proportion to the size of 



Fig. 638. 



Development of the sebaceous follicles in a six- 

 months' foetus, a, hair ; b, inner root-sheath ; c, outer 

 root-sheath ; d, rudimentary follicle. 



Magnified 250 diameters. 



Fig. 630. 



a, b, c, d, as above, but in a more advanced stage. 

 Magnified 250 diameters. 



