SEBUM. CERUMEN. 845 



the vernix caseosa. RUPPEL l found on an average in the vernix caseosa 

 348.52 p. m. water and 138.72 p. m. ether extractives, and also mentions 

 the presence of isocholesterin. These claims are disputed by UNNA. 2 

 In his experience isocholesterin does not occur in the vernix fat nor in 

 the sebum of man, although all kinds of sebum contain cholesterin. 



According to UNNA and GoLODETZ 3 the fat secretion (of the skin), 

 as the fat of the ball of the foot, and sebum are rich in oxy cholesterin, 

 while the cell fats of the outer skin does not contain any oxycholesterin, 

 The nails, .which are rather rich in oxycholesterin, are an exception. 



On account of the opinion generally held that the wax of the plant 

 epidermis serves as protection for the inner parts of the fruit and plant, 

 LiEBREiCH 4 has suggested that these combinations of fatty acids with 

 monatomic alcohols are the cause of the waxes having a greater resistance 

 as compared with the glycerin fats. He also considers that the choles- 

 terin fats play the r61e of a protective fat in the animal kingdom, and he 

 has been able to detect cholesterin fat in human skin and hair, in vernix 

 caseosa, whalebone, tortoise-shell, cow's horn, the feathers and beaks 

 of several birds, the spines of the hedgehog and porcupine, the hoofs of 

 horses, etc. He draws the following conclusion from this, namely, 

 that the cholesterin fats always appear in combination with the keratinous 

 substance, and that the cholesterin fat, like the wax of plants, serves 

 as protection for the skin-surface of animals. Of the sebum fats inves- 

 tigated by UNNA all contained, with the exception of the epidermis fat, 

 besides cholesterin, greater or smaller amounts of cholesterin ester. The 

 epidermis fat, on the contrary, was almost free from esters and consisted 

 chiefly of free cholesterin. 



In the fatty protective substance secreted by the Psylla alni, SUNDVIK 5 

 found psylla-alcohol, C 33 H 6 80, which exists there as an ester in combination with 

 psyllic acid, CsaHesCOOH. This alcohol has also been found in the wax of the 

 humble-bee. 



Cerumen is a mixture of the secretion of the sebaceous and sweat 

 glands of the cartilaginous part of the outer passages of the ear. It 

 chiefly contains soaps and fat, fatty acids, cholesterin and protein, and 

 besides these a red substance easily soluble in alcohol and with a bitter- 

 sweet taste. 6 



1 Hoppe-Seyler, Physiol. Chem., 760; Linser with Rohmann, Centralbl. f. Physiol., 

 19, 317; see also reference in ibid., 18, from Deutsch. Arch. f. klin. Med., 1904; Rtippel, 

 Zeitschr. f. physiol. Chem., 21; Ameseder, ibid., 52; Zumbusch, ibid., 59. 



2 Monatsch. f. prakt. Dermat., 45. 



3 Bioch. Zeitschr., 20. 



4 Virchow's Arch., 121. 



5 Zeitschr. f. physiol. Chem., 17, 25, 32, 53, 54 and 72. 



6 See Lamois and Martz, Maly's Jahresber., 27, 40. 



