322 



SECRETION. 



third with the lower two-thirds of the hair-follicle. The follicles of the long 

 hairs of the scalp are generally provided each with a pair of sebaceous glands, 

 measuring ji^to^ of an inch (0-21 to 0-34 mm.) in diameter. Encircling 

 the hairs of the beard, the chest, axilla and genital organs, are large glands, 

 some of them ^ of an inch (0-64 mm.) in diameter, arranged in groups of 

 four to eight. 



The glands connected with the follicles of the small, downy hairs are so 

 large, as compared with the hair-follicles, that the latter seem rather as ap- 

 pendages 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 curuncula lachrymalis, the penis 

 and the areola of the nipple, where they measure -fa to ^ of an inch (0-51 

 to 2'1 mm.). The glands connected with the downy hairs of other parts 

 usually are smaller. The glands of Tyson, situated upon the corona and 

 cervix of the glans penis, are sebaceous glands of the compound racemose 

 variety. 



The minute structure of the sebaceous glands is very simple. The folli- 

 cles 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, with an external layer of inelastic and small 

 elastic fibres, and are lined by cells. Next the membrane, the cells are poly- 

 hedric, pale and granular, most of them presenting a nucleus and a nucle- 



olus; but the follicle 

 itself contains fatty 

 granules and the other 

 constituents of the 

 sebaceous matter, with 

 cells filled with fatty 

 particles. These cells 

 abound in the seba- 

 ceous matter as it is 

 discharged from the 

 duct. The great quan- 

 tity of fatty granules 

 and globules found 

 in the ducts and fol- 

 licles of the sebaceous 

 glands renders them 

 dark and opaque when 

 FIG. ioo.-cerumi,i. M 0/iid (Sappey). examined with the 



Vertical section of the skin of the external auditory meatus : 1, 1. epi- 

 dermis : 2, 2, derma : 3, 3, series of hair-follicles'lodged in the sub- miCrOSCOpe bv tranS- 

 stance of the skin : 4, 4, series of sebaceous glands attached to these . . " , . 



follicles ; 5. 5. subcutaneous areolar layer : 6. 6, ceruminous glands ; mitted light, and their 

 7, 7, ceruminous glands with the ducts divided ; 8, 8, adipose vesicles. 



appearance is quite 



distinctive. The larger glands are surrounded with capillary blood-vessels. 



The ceruminous glands produce a secretion resembling the sebaceous 



matter in many regards, but in their anatomy they are almost identical with 



