28 



HEAD AND NECK 



surface of the eyeball ; consequently, when the lacrimal ducts 

 and the lacrimal sac are extirpated, a proceeding which is 

 necessary under certain circumstances, the patient suffers 

 little or no inconvenience from the overflow of tears, so long 

 as the secretion is not excessive. If the amount of secretion 



Lacrimal 

 gland, superior part 



Puncta lacrimalh 

 Lacrimal ducts 

 Lacrimal sac 



Medial palpebral 

 ligament 



Muco-periosteun 

 Plica lacrimalis 

 Inferior meatus 

 Inferior concha 



'F IG . 9 . Dissection of Lacrimal Apparatus. 



is greater than can be removed by evaporation, the excess, 

 under ordinary circumstances, passes through the puncta into 

 the ducts and thence through the lacrimal sac and naso- 

 lacrimal duct to the inferior meatus of the nose. If the 

 secretion becomes so abundant that it cannot be removed 

 by evaporation and drainage, part flows through the rima 

 as tears. 



