362 MEDICAL MYCOLOGY 



bilobed and relatively small, and are the sites of pityriasis, while those asso- 

 ciated with the area of lanugo hair are larger, multilobed, often racemose and 

 are found in the areas which furnish the sites of acne. Those associated with 

 hair follicles seem to function in oiling the hair shafts. 



Some of those not associated with hair follicles, are associated with the 

 sexual glands. Of these the mammary glands are the most conspicuous, but 

 smaller ones are found in the axilla, scrotum, prepuce, and labia which not 

 only lubricate these regions but also produce volatile fatty oils which impart 

 a distinct odor to the individual or to the species, the odor being especially 

 marked during the mating season. These glands may be infected with various 

 organisms which give rise to inflammation and abscess formation. Later in 

 life, retention cysts may form in them as a result of previous irritation. Other 

 sebaceous glands are concerned with the lubrication of the various orifices of 

 the body, e.g., the ceruminous gland of the ear, the meibomian glands of the 

 eyelids, the glands on the lips, those of the anal margin, etc. These glands 

 are often the seat of staphylococcal inflammation, the organisms being derived 

 from the scales in the scalp, resulting in abscesses of the external auditory 

 meatus, styes, retention cysts, etc. In the palmar and plantar surfaces, their 

 function is assumed by the sweat glands which produce small oil drops at the 

 extreme ends of the coiled glands. 



Sebum is an oily secretion, becoming cheesy on exposure to air. In 

 chemical nature, it is similar to lanolin (sheep's w^ool fat). Besides the fatty 

 acids, such as stearic and palmitic, there are volatile acids which impart the 

 characteristic odor. Sebum is not a true secretion like milk of the mammary 

 glands, but it is produced by the failure of the superficial layer of cells to 

 undergo keratinization. Instead, a fat vacuolization occurs until the whole 

 layer of cells is converted into sebum. In infections by Malassezia, the super- 

 ficial cells of the scalp undergo this same degeneration, producing the greasy 

 scales of dandrufi^. When Malassezia invades the sebaceous gland, it greatly 

 hastens the production of sebum. 



Since the sebaceous glands are not provided with a nerve supply, as are 

 the sweat glands, the regulation of flow is dependent on heredity, race, age, 

 sexual activity, customs and habits, diet, temperature, humidity, and perhaps 

 acidosis. Heredity probably determines the number of these glands and their 

 relationship to hair follicles and the function of the endocrine systems in gen- 

 eral, for often greasy skins with tendencies to acne and baldness are common to 

 several members of a single family. Little data regarding race have been ac- 

 cumulated that are not also explicable in connection with their habits and cus- 

 toms. Baldness is rare in women but, whether this is due to endocrine func- 

 tion or to the habit of wearing the hair long, thus preventing infection of the 

 scalp, or the development of the organism by the higher humidity, is un- 

 known. The fashion of wearing short hair is too recent in women to have 

 yielded conclusive evidence on this point. If baldness is linked with the 



