SEBACEOUS SECRETION. 



225 



Fig. 133. 



Y. THE LACHRYMAL FLUID. 



The lachrymal fluid is a clear, transparent fluid, the principal 

 elements of which are water, common salt, and an organic com- 

 pound called by some chemists lachrymine. Any mucus-corpus- 

 cles or epithelial cells in it 

 come from the mucous mem- 

 brane of the eyelids. 



Origin. This fluid is se- 

 creted by the epithelial cells 

 of the coeca of the lachrymal 

 gland. (Fig. 133.) 



Use. The lachrymal fluid 

 lubricates the eyeball, and 

 thus diminishes friction be- 

 tween it and the eyelid. In 

 case of copious weeping, 

 much of the fluid is merely 



a transudation, mixed With Conjunctival or inner surface of eyelid. I. Lachry- 

 mal gland, d. Orifices of its 7 ducts on the conjunctiva. 



the Secretion Of the lachry- The Meibomian glands are seen running towards the 

 i 1 j edges of the lids, o, o. Orbicularis muscle beyond the 



mal gland. lids (Sammering) 



CHAPTER IV. 



THE CUTANEOUS SECRETIONS. 



THE secretions of the skin are two ; the sebaceous secretion and 

 the perspiratory. 



I. THE SEBACEOUS SECRETION. 



This is secreted by the sebaceous follicles (glands), situated in the 

 substance of the corium of the skin. The Meibomian and the 

 ceruminous glands also belong to this class. 



The secretions of all these glands are by no means precisely 

 identical. In all of them, epithelial cells may be found as a mor- 

 phological element; the scaly cells of the skin often predominating 

 15 



