THE APPENDAGES OF THE EYE. 421 



cellular tissue lax, and contains no fat. The palpebral 

 fibres of the orbicularis are thin, pale, and more movable 

 than the rest of the muscle. The tarsal cartilages are two 

 thin, crescent-shaped fibroid structures, each about one 

 inch long, placed on the free margin of the lids, along 

 which they present a nearly straight, thick edge. Ex- 

 tending between the outer extremities of the tarsal carti- 

 lages are ligamentous fibres which are attached to the 

 malar bone. The inner extremities are attached to the 

 nasal and lachrymal bones by the tendo oculi. The 

 fibrous aponeurosis of the lids extends between the 

 border of the tarsal cartilages beneath the orbicularis 

 palpebrarum to the circumference of the orbit. 



The Meibomian glands are situated between the con- 

 junctivaB and the fibrous aponeurosis of the lids. They 

 are about fifty in number in both lids, less in the lower 

 than in the upper, and resemble miniature strings of 

 beads. They are disposed parallel to each other and 

 open on the free edge of the tarsal cartilage, which they 

 groove. They are compound sebaceous glands. 



The eyelashes or cilia are short, strong, curved hairs 

 which form a fringe to each lid. They are arranged in 

 a double or triple row and curve outward. The eye- 

 brows are two curved elevations of the skin above each 

 orbit and are covered with hair. 



The conjunctiva lines the under surface of the eyelids 

 and is reflected over the anterior part of the sclerotic and 

 cornea. It is a mucous membrane, thick and vascular 

 over the lids, loosely connected to the sclerotic ; non- 

 vascular and very thin on the cornea, but everywhere 

 abundantly supplied with nerves, The plica semi- 

 lunaris is a fold of the conjunctiva at the inner canthus, 

 at the outside of the caruncula lacrymalis, which is the 

 rounded, red elevation in the lacus lacrymalis. 



