OF THE GLANDS OF THE SKIN. 



223 



0*04) — 0-06'" broad. The glandular vesicles of the sebaceous 

 glands are either round, or pyriform and flask-shaped, or even 

 elongated or tubular. Their size varies exceedingly, from 

 006 — 0-16'" in length, 0-02 — 0-1'" in breadth, and is in the 

 mean. 004'" in the round ones; 0-08'" in length, 0-03'" in 

 breadth in the others. The excretory ducts also have very 

 different dimensions, sometimes long, sometimes short, broad 

 or narrow; the principal excretory ducts measure in the nose 

 and labia minora up to l J" in length, ^ — g" in breadth, and 

 have an epithelium 0-015 — 0-03'" thick. 



[The sebaceous glands on the glans penis, and on the inner 

 lamella of the prepuce or ' Tyson's glands/ are very incon- 

 stant, occurring sometimes only in a very small number, 

 sometimes in hundreds. They are ordinary sebaceous glands, 

 which are distinguished from those of other regions by their 

 not being connected with hair-sacs, and by their opening 

 independently on the surface of the skin. They may, 

 generally, be perceived by the naked-eye, as small whitish points 

 which do not project above 

 the skin ; and in sections 

 of skin, treated with caus- 

 tic soda or acetic acid, their 

 peculiarities may be readily 

 studied with the microscope. 

 They appear to be sometimes 

 tubular, at others simply 

 racemose; the former pre- 

 sent a round or pyriform 

 follicle of 0-048—0-12'" in 

 diameter, and a straight ex- 

 cretory duct of i'" in length, 

 and 0024 — 0-035'" breadth ; the latter have 2— 3, or at most 5, 

 terminal vesicles, and measure 0-08 — 0-18'" altogether. The 

 aperture of both kinds of glands, which have a diameter of 

 0-02 — 0-06'", are easily seen. With regard to the position of the 



Fig. 86. Two sebaceous glands ; the larger, 1, from the inner lamella of the pre- 

 puce; the smaller, 2, from the glans penis, x 50 : a, glandular epithelium continued 

 into the stratum Malpighii of tin skin ; b, c, contents of the gland, with scattered 

 larger fat-drops; g, horny layer of the epidermis projecting somewhat into the 

 duct. 



