288 SECRETION 



mode of formation can be formed from microscopical examinations. If 

 a small quantity is scraped from the surface and is spread out upon a 

 glass slide with a little glycerin and water, it will be found, on micro- 

 scopical examination, to consist of a large number of epithelial cells with 

 a few small fatty granules. These cells, after desiccation, constitute 

 about ten per cent of the entire mass. The fatty granules are few and 

 do not seem to be necessary constituents of the vernix, as they are 

 of the sebaceous matter. In fact, the vernix caseosa must be regarded 

 as the residue of the secretion of the sebaceous glands rather than an 

 accumulation of true sebaceous matter. 



The office of the vernix caseosa is protective. In making a micro- 

 scopical preparation of the cells with water, it becomes evident that the 

 coating is penetrated by the liquid with difficulty, even when mixed with 

 it as thoroughly as possible. The protecting coat of vernix caseosa 

 allows the skin to perform its office in utero ; and at birth, when this 

 coating is removed, the surface is found in a condition perfectly adapted 

 to extra-uterine existence. 



Cerumen. A peculiar substance of a waxy consistence is secreted 

 by the glands that have been described in the external auditory meatus, 

 under the name of ceruminous glands, mixed with the secretion of 

 sebaceous glands connected with the short hairs in this situation. It is 

 difficult to ascertain what share these two sets of glands have in the for- 

 mation of the cerumen. The waxy portion of the secretion probably 

 is produced by the sebaceous glands, and the convoluted glands, com- 

 monly known as the ceruminous glands, produce a secretion resembling 

 sweat. This view is to a certain extent reasonable ; for the sebaceous 

 matter is not removed from the meatus by friction, as in other situations, 

 and would have a natural tendency to accumulate ; but the contents of 

 the ducts of the ceruminous glands differ materially from the liquid 

 found in the ducts of the ordinary sudoriparous glands, containing 

 granules and fatty globules such as exist in the cerumen. Although the 

 glands of the ear are analogous in structure, and to a certain extent in 

 the character of their secretion, to the sudoriparous glands, their secre- 

 tion is peculiar. The perspiratory glands of the axilla and of some other 

 parts also produce secretions differing somewhat from ordinary perspira- 

 tion. So far as can be ascertained, the cerumen is produced by both 

 sets of glands. The sebaceous glands attached to the hair-follicles 

 probably secrete most of the oleaginous and waxy matter, while the so- 

 called ceruminous glands produce a secretion of much greater fluidity, 

 but containing granular and fatty matters. 



The consistence and general appearance of cerumen are variable 

 within the limits of health. When first secreted, it is of a yellowish 



