398 HISTOLOGY 



exceptional cases as at the margin of the lip or on the labia minora, they 

 occur independently of hairs. They vary in size from 0.2 to 2.2 mm., the 

 largest being found in the skin of the nose where the ducts are macro- 

 scopic. None are found in the palms or soles, where hairs also are absent. 



The short duct is a prolongation of the outer epithelial sheath of the hair 

 and is formed of stratified epithelium, the number of layers of which de- 

 creases toward the alveoli. The alveoli consist of small cuboidal basal 

 cells, and of large rounded inner cells in all stages of fatty metamorphosis. 

 As the cell becomes full of vacuoles, the nucleus degenerates, and the cell 

 is cast off with its contained secretion. In life the product of the glands is 

 a semi-fluid material, composed of fat and broken-down cells. 



Glandules prczputiales are sebaceous glands without hairs which are 

 sometimes, but not always, found on the glans and praeputium penis. 

 The designation "Tyson's glands" is not justified since Tyson described 

 the epithelial pockets ^ to i cm. long which regularly occur near the fren- 

 ulum praeputii. Praeputial glands and crypts are not found in the embryo. 

 The praeputium is united to the outer surface of the glans by an epithelial 

 mass, which often persists after birth and is broken up by the formation 

 of concentric epithelial pearls. Glands and crypts are absent from the 

 praeputium and glans of the clitoris. 



SWEAT GLANDS. 



The glandula sudoripara are long unbranched tubes terminating in a 

 simple coil (described by Oliver Wendell Holmes as resembling a fairy's 

 intestine, Fig. 410). The coil is found in the deep part of the corium or 

 in the subcutaneous tissue (Fig. 387). The duct pursues a straight or 



somewhat tortuous course to the epidermis 

 which it enters between the connective tissue 

 papillae. Within the epidermis its spiral wind- 

 ings are pronounced (Fig. 387); it ends in a 

 pore which may be detected macroscopically. 



The epithelium of the ducts consists of two 

 or three layers of cuboidal cells; it has an inner 

 cuticula, and an outer basement membrane 

 FIG> ^ RroF OD A EL sw E T A H T E oT^D covered by longitudinal connective tissue fibers. 



FROM THE SOLE OF THE FOOT. tiT'.i ji *J . 11 J r 11 



(After Huber.) Within the epidermis its walls are made of cells 



of the strata through which it passes. The 



secretory portion of the gland (3.0 mm. long according to Huber) forms 

 about three-fourths of the coil, the duct constituting the remainder. The 

 secretory epithelium is a simple layer of cells, varying from low cuboidal 

 to columnar, according to the amount of secretion which they contain. 

 Those filled with secretion present granules, some of which are pigment and 



