414 



SEBACEOUS FOLLICLES. 



Fig. 108. Fig. 108, represents the orifices of the 



sebaceous glands, as they are seen in 

 the nose, after it has been deprived of 

 its epidermis. Each follicle consists 

 of a depression or doubling in- 

 wards of the cutis vera, which be- 

 cornjes more vascular and thin where 

 it forms the walls of the follicle. The 

 sebaceous follicles, according to E. 

 Weber, are much larger than and en- 

 tirely distinct from those forming the 

 bulbs of the hairs. The latter, too, 

 are situated more deeply, being often 

 found in the subcutaneous cellular 

 tissue. They differ also, according to him, in their structure ; 

 each sebaceous follicle being composed of four or five com- 

 partments or cells agglomerated together. They are also 

 larger than those of the bulbs of the hairs ; the largest diameter 

 of a sebaceous gland, (the transverse,) observed by Dr. Weber, 

 was three-fourths of a line. 



Muscular fibres have been supposed by some persons to 

 exist in the skin, but such fibres have never been demonstrated 

 in it. The skin of the scrotum is often much contracted, but 

 the fibres which produce this effect are very visible in the 

 cellular membrane, and have a muscular appearance. 



Although the skin is not muscular, it sometimes changes its 

 appearance in a surprising manner. 



When the surface of the body is suddenly exposed to cold, 

 or when the chill of fever exists to a considerable degree, the 

 skin will contract very sensibly, and, at the same time, a great 

 number of conical papillae will project from its surface. This 

 constitutes the Cutis Anserini ; and is supposed to be produced 

 by a sudden contraction of the vessels in the skin, which forces 

 out their contents, and of course, diminishes its bulk ; while the 

 papillae do not contract in the same degree, and, therefore, are 

 somewhat projected. Vide, article, contractile tissue. 



When the skin is free from disease, the two exterior laminae, 



