CHAP. XIV.] ENTOZOA OF THE SEBACEOUS GLANDS. 



425 



in most parts of the skin, but are absent from the palms and soles. 

 They are most abundant on the scalp and face (especially about the 

 nose), and about the anus and scrotum. The glandula odorifera 

 of the genital organs are a variety of them, only remarkable by 

 their secretion. The orifices open either on the general surface, 

 or into the hair-follicles, and they lie either in the cutis or sub- 

 dermoid tissue, according to their size. They are usually asso- 

 ciated with the hairs, in the manner represented in fig. 92. They 

 consist of a more or less capacious duct, generally branched, and 

 terminating in blind, pouch-like extremities. The basement mem- 

 brane of these glands is thicker than that of the sweat-glands, 

 and is lined by an epithelium, in the particles of which are in- 

 cluded granules of sebaceous matter. The terminal vesicles and 

 the ducts are filled with an accumulation of this epithelium, which, 

 having been detached from the walls, constitutes the secretion. On 

 the deep or parenchymal surface of the basement membrane a web 

 of capillary vessels is spread out. 



While speaking of the sebaceous glands, we must say a few words 

 of a parasite so generally found in their ducts in many parts of the 

 body, that it may almost be regarded as a denizen. This was recently 

 discovered by Dr. Simon, of Berlin,* and has been further describ- 

 ed by Mr. Wilson, f who 

 speaks of two principal 

 varieties of the adult ani- 

 mal, chiefly distinguished 

 by their length ; the one 

 measuring from T ^ to 

 -Jj-, the other from r J-Q to 

 yj-g of an inch. He de- 

 tails several interesting 

 particulars concerning 

 their structure and de- 

 velopment, for which we 

 must refer to the original 

 memoir. These singular 



OVA f/vnnrl in 1 



" 



Entozoa from the sebaceous follicles, a, Two seeniii their 

 ordinary position in the orifice of one of the sebaceous follicles 



most every individual, and of tne SCU P- * short variet y- c - Lon e variel y- 

 especially in those possessing a torpid skin, and they multiply in 

 sickness. In living and healthy persons from one to three or four 

 may be found in each follicle." We have represented them as we 

 have found them in a sebaceous follicle of the scalp (fig. 93) . 

 * Miiller's Archiv., June, 1842. t Phil. Transact. 1844. 



