418 THE SENSORIAL FUNCTIONS. 



the contact is complete : by this means the tears 

 are carried onwards in that direction, and accumu- 

 lated at the inner corner of the eye ; an effect 

 which is promoted by the bevelling of the margins 

 of the eye-lids, which, when they meet, form a 

 channel for the fluid to pass in that manner. When 

 they arrive at the inner corner of the eye, the tears 

 are conveyed away by two slender ducts, the ori- 

 fices of which, called the puncta lacrymnlia (p, p), 

 are seen at the inner corner of each eye-lid, and 

 are separated by a round projecting body (c), con- 

 nected with a fold of the conjunctiva, and termed 

 the lacrymal caruncle. The two ducts soon unite to 

 form one passage, which opens into a sac (s), si- 

 tuated at the upper part of the sides of the nose, 

 and terminating below (at n) in the cavity of the 

 nostrils, into which the tears are ultimately con- 

 ducted. When the secretion of the tears is too 

 abundant to be carried off by this channel, they 

 overflow upon the cheeks ; but when the quantity 

 is not excessive, the tendency to flow over the eye- 

 lid is checked by an oily secretion proceeding from 

 a row of minute glands, situated at the edge of the 

 eye-lids, and termed the Meibomian glands. 



The eye-brows are a further protection to the 

 eyes ; the direction of the hairs being such as to 

 turn away from them any drops of rain or of per- 

 spiration, which may chance to fall from above. 



Excepting in front, where the eyes are covered 

 and protected by the eye-lids, these important 

 organs are on all sides effectually guarded from 

 injury by being contained in a hollow bony socket, 

 termed the orbit, and composed of seven portions 

 of bone. These seven elements may be recognised 



