THE CUTANEOUS GLANDS. 



335 



uals. In the case of the ceruminous glands, the amount of oil and pigment is 

 constantly great and confers the distinguishing characteristics of the ear-wax. 

 On leaving the gland-coil, in close proximity to the blind end of the 

 gland, the duct ascends through the corium with a fairly straight or 

 slightly wavy course as far as the epidermis. On entering the latter its 

 further path is marked by conspicuous corkscrew-like windings, which ter- 

 minate on the surface by a trumpet-shaped orifice, the sweat-pore. In its 



SSRSS 



<*^iM 



s 



r^Sfe^'' i I ^ISfer- 



S. lucidum 

 S. granulosum 



S.germinativum 



Duct of 

 sweat-gland 



agg 



^vM "l:s 



f^:. Fat-cells 



Coiled part of 

 sweat-gland 



FIG. 381. Section of skin from palm, showing layers of epidermis and parts of sweat-glands extending 

 from surface into tela subcutanea. X 65. 



course through the corium the duct never traverses a papilla or ridge, but 

 always enters the cuticle between the elevations. On the palms and soles, 

 where the pores occupy the summit of the cutaneous ridges, the ducts enter 

 the cuticle between the double rows of papillae. 



The sudden and conspicuous reduction in the size of the tube, which 

 marks the termination of the secreting segment and the beginning of the 

 duct, is accompanied by changes in the structure of its wall. In addition to 

 a reduction of its diameter to one half or less of that of the ampulla, the duct 

 loses the layer of muscle and becomes flattened, with corresponding changes 

 in the form of its lumen. The single row of secreting elements is replaced 

 by an irregular double or triple layer of cuboidal cells, which exhibit a 



