SEBACEOUS FLUIDS. 



359 



The glands connected with the larger hair-follicles are of the simple racemose variety 

 and are from T |^ to -fa of an inch in diameter. From two to five of these glands are gen- 

 erally found arranged around each hair-follicle. They discharge their secretion at about 

 the junction of the upper third with the lower two-thirds of the hair-follicle. The folli- 

 cles of the long hairs of the scalp are generally provided each with a pair of sebaceous 

 glands, measuring from T |^ to ^ of an inch in diameter. Encircling the hairs of the 

 beard, the chest, axilla, and genital organs, are large glands, some of them 5 V f an inch 

 in diameter, arranged in groups of from four to eight. 



The glands connected with the follicles of the small, downy hairs are so large, as com- 

 pared with the hair-follicles, that the latter seem rather as appendages to the glandular 

 structures. These glands are of the compound racemose variety and present sometimes 

 as many as fifteen culs-de-sac. The largest are found on the nose, the ear, the caruncula 

 lachrymalis, the penis, and the areola of the nipple, where they measure from / - to T ^ 

 of an inch. The glands connected with the downy hairs of other parts are usually small- 

 er. The glands of Tyson, situated upon the corona of the glans penis and behind, upon 

 the cervix, are sebaceous glands of the compound racemose variety. 



FIG. 99. Sebaceous giands. (Sappey.) 



A, a gland in its most rudimentary form : 1, rudimentary hair-follicle; 2, downy hair; 3, simple sebaceous follicle. B, 

 a gland more developed : 1, hair-follicle ; 2, simple sebaceous follicle. 0, a gland with two follicles : 1 , hair- follicle ; 

 2, simple follicle ; 3, follicle imperfectly divided. D, a compound gland : 1, hair-follicle ; 2, lobule with three folli- 

 cles; 8, lobule with four follicles. E, a gland with four lobules: 1, hair-follicle ; 2, 2, first lobule; 3, second lobule; 

 4, 4, third lobule ; 5, fourth lobule ; 6, excretory duct with a hair passing through it. F, a gland with four lobules : 

 1, hair-follicle ; 2, 2, first lobule; 3, second lobule ; 4, third lobule ; 5, fourth lobule; 6, excretory duct. 



The minute structure of the sebaceous glands is very simple. The follicles which 

 compose the simple glands and the follicular terminations of the simple and compound 

 racemose glands are formed of a delicate, structureless or slightly granular membrane, 



