SECT. 



3-] 



SEBACEOUS GLANDS. 



13S 



C— OF THE SEBACEOUS GLANDS. 



^ 73. These are small, whitish glands, which are found over 

 almost the whole extent of the skin, and yield its fatty secretion, 

 tebum cutaneum. Their form is very various. The simplest (fig\5gA) 

 are pyriform or short tubular pouches; 

 in others — the simple racemose — two, 

 three, or even more follicles or saccules, 

 are united by a shorter or longer pedicle ; 

 in others, again (figs. 59B and 60), two, 

 three, or more clusters of saccules are 

 connected by a common duct, and form 

 a compound racemose gland. Besides 

 these three forms, which represent only 

 the chief varieties, there are various in- 

 termediate forms, which do not require a 

 detailed description. 



The sebaceous glands principally occur 

 in parts covered with hair, and open on 

 the surface in conjunction with the hair- 

 follicles : on which account thev have also 

 been termed qlands of the hair-follicles. 

 In all the coarser hairs, the glands appear 

 as lateral appendages of the hair- follicles, 

 and open into the latter by narrow ex- 

 cretory ducts (fig. 59B). In woolly hairs, 

 on the other hand, the gland-ducts and 

 the hair-follicles are either nearly equally 

 large, and open into a common canal, 

 which may, with equal reason, be re- 

 garded as a continuation of the one or of 

 the other ; or the glandular canals pre- 

 ponderate (fig. 60) and the hairs pass into 

 a subordinate relation, so that their fol- 

 licles terminate in the glands, or even 

 open at the orifice of the glands. 



In places destitute of hair, sebaceous 

 glands are found only in the labia mi- 

 nora, the glans and prepuce of the penis, 

 but are not present on the glans and 

 prepuce of the clitoris. In general the 

 glands lie close to the hair-follicles in the more superficial part of 

 the cutis, and are larger in connection with small than with large 



nose, 

 Sim- 

 hair. 



Sebaceous glands from the 

 magnified about 50 times. A. 

 pie tubular gland without 

 B. Compound gland, opening in com- 

 mon with a hair-follicle, a. glandular 

 epithelium, continuous with b. the 

 mucous layer of the epidermis ! c. con- 

 tents of the glands, sebaceous and free 

 fat cells ; d. the separate racemes of 

 the compound glands; e. hair follicle 

 (root-sheath) with the hair/. 



