IX 



THE SKIN AND CUTANEOUS GLANDS 



485 



high power, these ridges are divided not only by longitudinal 

 furrows, but also at short and fairly regular intervals by less 

 profound transverse furrows with a minute funnel-shaped orifice 

 in the middle of each, which is the mouth of a sweat-gland 

 (Fig. 134). 



II. The Sudiferous or Sweat - Glands, already known to 

 Stensen, Malpighi, Boerhaave and others, and more exactly located 

 as regards their orifices by Eichhorn (1826), were first described 

 accurately and almost simultaneously by Purkinje, Wendt, 

 Breschet (1834), and Gurtl (1835), not only for man but also for 



FIG. 134. (Left.) Four ridges of the epidermis, with short furrows across them, and the orifices 

 of the sudoriferous ducts. (Breschet.) 



FIG. 135. (Right.) Section of a sweat gland in the human skin. (Schafer.) a, a, secreting tube 

 in transverse section ; b, part of secreting tube seen from above (surface focus) ; c, c, efferent 

 tube (commencing duct) ; d, intertubular connective tissue with blood-vessels. In the section 

 across the secreting tube, 1 is the basement membrane ; 2, the muscular fibres cut across ; 

 3, the secreting epithelium lining the tube. 



the domestic animals. They consist of long tubes in which the 

 secreting part is coiled up into a ball, seated at varying depths of 

 the corium and in the first layers of the subcutaneous adipose 

 tissue (Fig. 129). The excretory duct or conducting tube is con- 

 tinued from the coiled gland through the corium, and in a spiral 

 course through the epidermis, opening between two adjacent 

 papillae with the widened orifice described above. The secreting 

 tube is considerably larger than the duct, and has a wider lumen 

 (Fig. 135). It has a basement membrane, plain muscular fibres, 

 and one or two layers of columnar cells characterised by a very 

 distinct cuticular lining. The excretory duct is covered with a 

 single layer of cells, which are smaller and have no true cuticle. 

 Although direct evidence is wanting, it is probable on analogy 



