SWEAT-FOLLICLES SEBACEOUS GLANDS. 23 



the lymphatics and blood-vessels, which arise from the 

 skin or terminate in it ; and the follicles or glands, which are 

 situated in the substance of the dermis, according to most 

 authors, but in the subcutaneous adipose tissue, according to 

 Robin. These send the product of their secretions by 

 special ducts to the epidermis. These ducts traverse the 

 substance of the skin sometimes in straight and sometimes 

 in twisted lines, and give passage, some to hairs, to the 

 beard and to products of this nature which are formed in 

 the bulb of the hair-follicles ; and others, to the secretions of 

 the swsat-follicles and the sebaceous glands. The orifices of 

 the sweat-follicles, situated at the base of the papillae, exhale 

 the secretion in the form of insensible perspiration, or in 

 the form of little drops on the surface of the skin. Those 

 of the sebaceous glands open, some into the hair-ducts, and 

 others on the surface of the epidermis, and furnish to that 

 membrane and its dependencies a fatty substance which 

 seems to be designed to preserve the softness of the skin, 

 and to protect it from injury or change from the sweat; we 

 find them therefore in the greatest abundance at those 

 points where the transpiration is most active. 



Of these glands and follicles of which the microscope 

 shows us the details, some attain the size of a grain of millet, 

 but most of them hardly reach a millimetre in diameter. 

 Their orifices are on the surface of the epidermis, a point 

 long disputed, but now admitted by anatomists. But these 

 orifices are not what were formerly denominated pores. It 

 was supposed that there were gaps or spaces in the skin 

 analogous to those in a sieve, and that the cutaneous secre- 

 tions issued from these gaps; but neither in the epidermis 

 nor in the skin are there any such gaps, and it will be seen 

 from the preceding description wherein the doctrines of the 

 ancients differ from, and wherein they resemble, those of our 

 own day. 



The epidermis is regarded by anatomists as impermeable, 

 and yet experiment proves that even the perfect skin allows 

 gases and fluids to penetrate the organism. If we do not 

 admit that this absorption takes place through orifices at 

 the surface of the epidermis, and if we suppose it to take 



