THE LACHRYMAL APPARATUS. 211 



Eyelashes, or Cilia , are a double or triple row of short hairs, situated on 

 the free margins of the lids; their follicles lying in the connective tissue 

 beneath the tarsal cartilages. 



Arteries, are the Palpebral branches of the ophthalmic artery, forming 

 the Superior and Inferior Tarsal Arches, and anastomosing with the 

 angular, anterior temporal, lachrymal and transverse facial. 



Nerves, the 3d, facial and sympathetic to the muscles; the 5th to the skin 

 and conjunctiva. 



What is the Conjunctiva ? It is the mucous membrane which lines the 

 eyelids, and is reflected over the front of the sclerotic and cornea. It is con- 

 tinuous with the mucous lining of the Meibomian glands, canaliculi, lachry 

 mal sac, nasal duct, lachrymal duct and gland. The 



Palpebral Conjunctiva, consists of connective tissue covered by epithe- 

 lium, is traversed by furrows, and has papillae and follicular glands. 



Ocular Conjunctiva, is very thin and transparent, loosely attached on the 

 sclerotic, firmly adherent over the cornea, where it has no vessels in its 

 structure. It has very few papillae, and no glands. 



Retro-tarsal or Palpebral Folds, superior and inferior, are where the con- 

 junctiva is reflected over the globe. They contain prominent papillae, and 

 conglomerate glands, called the accessory lachrymal glands. 



Plica Semilunaris, or Semi-lunar Folds, a crescentic fold of conjunctiva 

 at the inner canthus, considered to be the rudiment of the Membrana 

 Nictitans or 3d eyelid (of birds). 



What is the Caruncula Lachrymalis ? It is a small, red, conical body, 

 situated in the lacus lachrymalis, at the inner canthus of the eye ; consisting 

 of hair follicles and sebaceous glands, and covered by conjunctiva. It is con- 

 nected by tendinous fibres to the capsule of Tenon and to the rectus internus 

 muscle. 



Name the parts constituting the Lachrymal Apparatus. They are 

 the lachrymal gland and its ducts, the accessory conjunctival glands, the 

 canaliculi, lachrymal sac, and nasal duct. 



Describe the Lachrymal Gland. It is an oval gland situated in a fossa 

 of the orbital portion of the frontal bone, at the outer angle of the orbit, its 

 inferior surface resting on the eyeball, its lower margin or lobe being covered 

 by conjunctiva. The 



Tarso-orbital Fascia, connects the lachrymal gland to the bony roof of 



the orbit. 

 Ducts, 6 to 1 2 in number; open on the upper and outer portion of the 



palpebral conjunctiva. 

 Secretion (tears), lubricates the anterior surface of the eyeball. Excess 



