SKIN AND ITS APPENDAGES. 129 



The sebaceous or oily fluid comes from sebaceous glands. 

 These, though not so numerous as the perspiratory, are 

 nevertheless abundant in many parts of the skin, as the 

 nose, face, arm-pits, arms, &c.; the palms of the hands and 

 soles of the feet being destitute of them. They present a 

 variety of form, from the simple sac-like follicle to the 

 lobulated gland. In the scalp the lobes are clustered to- 

 gether like a bunch of grapes ; and their ducts, which are 

 straight, though sometimes spiral, besides perforating the 

 skin, have one or more of them entering the hair follicle. 

 (Fig. 19.) These ducts are lined by the involuted cuticle. 

 The meibomian glands of the eye-lids, and the ceruminous 

 glands of the ear, are also examples of sebaceous glands. 



The sebaceous glands are about the size of millet seed, 

 of a yellow color, and most generally situated, as well as 

 the perspiratory, in the subcutaneous cellular structure, 

 though sometimes imbedded in the dermis itself. 



There is another set of glands belonging to the skin, 

 called the odoriferous glands, (glandules odoriferse,) which 

 are very particularly described by Dr. Homer, who seems 

 to have given them more attention than any previous 

 anatomist. He says they are well developed in the negro, 

 and are found in the arm-pit, near the skin, and enveloped 

 in cellular adipose structure. About three hundred of 

 these glands were counted on a space the size of a Spanish 

 dollar ; they are described as of a brown color, of varying 

 size, from a line to two lines in length, and having a gran- 

 ular surface, like the mammary and pancreatic glands. 

 Their use is believed to be to furnish the odorous secretions 

 of the body. 



The Functions of the skin are those of Sensation, Secre- 

 tion, and Absorption. 



Sensation, as already stated, is either general or special 

 every part of the skin being supplied with nerves so, in 

 every part we find common sensibility, or tact, while spe- 

 cial sensibility, or sense of touch, is very limited, confined 

 almost exclusively to the tips of the fingers. By this func- 

 tion the health and preservation of the body is particularly 

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