OF THE GLANDS OF THE SKIN. 227 



soon completely filled with moderately large, round, dark, fat 

 granules. They thus proceed towards the excretory ducts; and 

 the fat drops contained in them running more and more together, 

 and the membranes themselves becoming rather more resistant, 

 they eventually assume the form of the sebaceous cells above 

 described. The free fatty matter in the sebaceous secretion is 

 formed, in certain cases, by the solution of the cells whilst 

 still in the interior of the glandular vesicles, for, in fact, in 

 many glands, free fat, in smaller or larger, often very con- 

 siderable drops (fig. 86 B), is met with, even in the terminal 

 vesicles; however, it is also, perhaps, produced in consequence 

 of its draining from closed cells, a supposition which is not 

 a little strengthened by the circumstance, that the fat-con- 

 taining cells in the excreted sebaceous matter, are seldom filled 

 to distension, but appear for the most part variously flattened, 

 or even corrugated, and contain only a small quantity of fat. 

 Understood in this way, the formation of the cutaneous 

 sebaceous matter resembles in many respects that of the cuticle. 

 The young, easily soluble cells at the bottom of the glandular 

 follicles may be compared to the Malpighian cells of the 

 epidermis, and the less soluble ones of the secretion filled with 

 fat, to the horny plates, which seems the more appropriate, if 

 we consider, 1, that the deep layer of the epidermis of the 

 hair-sac is continued into the ducts of the glands, and even the 

 outermost cells of the terminal vesicles; and 2, that the 

 epidermis, in some situations being constantly detached, forms 

 secretions (I refer to the smegma prceputii of the penis and 

 clitoris), substances which are, moreover, to all appearance 

 chemically allied to the sebaceous secretion ; for the latter, it 

 may be remarked, according to an analysis of the contents of a 

 distended gland byEsenbeck (Gmelin's 'Handbuch der Chemie/ 

 Bd. II), contains principally, fat, 24*2 ; albumen and casein, 

 24-2; extractive matters, 24; and phosphate of lime, 20 per cent. ; 

 substances which are found, at all events in part, in the smegma. 

 Of nerves, I have seen no indication in the sebaceous glands, 

 nor of vessels distributed upon and between their lobules; 

 whilst numerous minute vessels and even capillaries, undoubt- 

 edly exist around the larger glands, most distinctly in the 

 penis and scrotum, as well as in the ear. I would, moreover, 

 refer to the smooth muscles described above, when speaking of the 



