404 NERVOUS SYSTEM. 



The Lachrymal Gland (Glandula Lachrymalis] is situated 

 in the orbit, immediately below and within the external angu- 

 lar process of the os frontis. It secretes the moisture that lu- 

 bricates the eyelids and eyeball, and which, when it becomes 

 abundant, is called the Tears. It is a flattened oblong or oval, 

 convex above and concave below, of ten lines in length, six in 

 width, and about two lines at its thickest part, for its edges are 

 somewhat bevelled. It may be considered as divided into two 

 parts or lobes, of which the^superior is the larger and occupies 

 the depression attributed to it in the frontal bone, while the in- 

 ferior, being the smaller, is placed at the anterior margin of the 

 depression.* It is lined below by the conjunctiva, and is pro- 

 tected in front by the margin of the orbit which it touches. 



This gland resembles much a salivary gland in its light pink 

 colour, and in its consisting in a congeries of lobules united by 

 cellular substance. Unless we are to consider the latter as 

 such, it has no regular capsule. From the .lachrymal gland 

 there proceed six or seven excretory canals, extremely fine, 

 and found with so much difficulty that many distinguished ana- 

 tomists have sought for them in vain.t The orifices of these 

 ducts have been laid down by Soemmering, as equi-distant; 

 forming in the conjunctiva, a row half an inch long, and pa- 

 rallel with the superior margin of the upper tarsus cartilage, 

 beginning a quarter of an inch above its external end and going 

 inwards. By squeezing the gland, small drops like tears, will 

 appear on the nearest surface of the conjunctiva, but not in 

 the regular order laid down by anatomists for the lachrymal 

 orifices. 



The Lachrymal Ducts (Canaliculi Lachrymahs) are situated 

 immediately beneath the skin, at the internal commissure of the 

 eyelids, in their posterior margin, and behind the orbicularis 

 muscle. There is one for each eyelid. They are about half 



* These lobes are frequently marked off by a ligamentous band passing from 

 between them to the external angular process. 



t These are Morgagni,.Haller, Zinn, and Durverney. Meckel, Scemmering, 

 and many others, speak with all confidence concerning them. Bichat admits 

 that he only acknowledges their existence inductively. Dr. Monro, of Edinburgh, 

 claims to have discovered them by plunging the eye into a coloured fluid which 

 was absorbed by them. Dr. W. Hunter seems to have a prior claim to Dr. 

 Monro. See Med. Comment, p. 54. Mascagni also acknowledges their exist- 

 ence: Prodrome della Grande Anatomia, vol..i. p.. 60.. 



