LACHRYMAL GLAND. 403 



surface covered by the tunica conjunctiva, viz. the anterior part 

 of the eyeball and the internal surfaces of the eyelids, should 

 be kept perfectly flexible and moist ; for this purpose the lach- 

 rymal fluid is constantly secreted, in varying quantities, tfy the 

 lachrymal gland, formerly called Glandula Innominata.* 



This body is situated in a depression, in the upper surface of 

 the orbit, near its external margin : it is exterior to, and above, 

 the tunica conjunctiva. It is of an irregular oblong form, and 

 rather flat ; but it has some thickness. The under surface is 

 lobulated, and forms two principal lobes. 



From the anterior edge of the gland the excretory ducts, to 

 the number of six or seven, pass off. They terminate at a short 

 distance from the gland, near the upper end of the cartilage, 

 and near the external angle of the eye. They do not commu- 

 nicate with each other. 



These ducts are so small, that they are not often seen by 

 the naked eye; but there is sometimes a chain of smaller glands, 

 which lie between the gland and the eyelid, nearly in the direc- 

 tion of the ducts. This is called the palpebral portion of the 

 lachrymal gland, and is of small size. 



The layer or orbital portion of the lachrymal gland, is 

 about the size of an almond, and consists in a great number of 

 little fleshy granules of a reddish white color, in which the 

 extreme branches of the arteries terminate, and from which, 

 minute excretory ducts are believed to originate. The granules 

 are separated from each other by processes of cellular tissue, 

 which are sent in by the general cellular envelop of the gland, 

 and by nerves and blood-vessels. The excretory ducts originat- 

 ing from these glandular grains, form by inosculation the ducts 

 above mentioned, which open through the conjunctiva. The 

 orifices of these ducts in the conjunctiva, are readily seen in the 

 eye of bullocks, but in the human eye, cannot well be discovered, 

 without some artificial preparation. 

 After immersing the human eye, for some time in water 



* The necessity of this gland, exists only in land and amphibious animals, 

 in which the eye is exposed to the evaporating effects of the air. In fishes, 

 &c., it is not met with. The eyes in them being moistened by the fluid in 

 which they live. p. 



