i 
r LACRYMAL ORGANS. 
% 
_ sion of a size sufficient to receive the point 
; the thumb, situated in the roof of the 
orbit at its upper and outer angle, just 
_ within the overhanging outer extremity of 
the superciliary arch. The superior lacrymal 
‘gland is’ of an oval or triangular shape about 
‘three-fourths of an inch in its longest diameter 
and about half an inch across. It is flattened 
from above downwards. Its upper surface is 
convex; its lower plane or concave. The 
thickest edge of the gland is turned outwards. 
The gland is of a reddish colour and is en- 
eloped in a thin but dense cellular coat. The 
dwer mass of the lacrymal gland, or glandula 
malis inferior, is a loosely connected ag- 
ation of lobules of the same glandular 
substance as the above. It was first described 
by the second Monro, who called the lobules, 
for distinction’s sake, glandule congregate.* 
_ The lower mass of the lacrymal gland is 
he smaller than the upper, with which it is in con- 
. t et above, whilst below it extends to the outer 
part of the upper margin of the tarsal cartilage of 
upper eyelid. It lies indeed in the substance 
of the upper eyelid at the outer part. It is seen 
‘shining through the conjunctiva in everting the 
ri per eyelid. 
mae! 
- Laerymal gland, left side. 
_@a, Superior mass; bb, inferior mass; c, part 
| of inferior mass lying towards the outer canthus. 
Intimate structure of the lacrymal gland.— 
_ The lacrymal gland is what is commonly called 
| conglomerate. It belongs to Miiller’s com- 
pound glands with canals of the ramified type. 
_ “Inthe arrangement of the secreting canals 
_ of the lacrymal glands,” says Miiller,+ “ two 
| principal forms are observed: the one is that 
which I discovered in the chelonian reptiles ; 
the other, that which prevails in birds and 
ammalia. In the chelonia, the gland is 
formed of a number of club-shaped lobes, 
“united together by means of the different ducts 
which run in their interior. The duct of each 
lobe is pretty uniform in diameter, and into it 
“Open an innumerable quantity of microscopical 
ts of coeca, which are arranged around it 
5. * Monro’s Observations, Anatomical and Phy- 
logical, wherein Dr. Hunter’s claim to some dis- 
Goveries is examined, p. 77. Edinburgh, p. 77. 
d senmuller, Partium Externarum oculi humani, 
‘Imprimis organorum lacrymalium descriptio anato- 
| mica, &c. § 109. Lipsie, 1810. 
_. + Handbuch der Physiologie des Menschen, 
Bd.1i. S. Or, Translation by Baly, p. 445. 
| See also ** De glandularum secernentium penitiori 
‘Structura, p. 51, 52, tab. v. figs. 3, 4, 5, & 8. 
4 
i 
iw 
fs 
a 
89 
at right angles like the foliage of a moss on its 
stem.” In birds, in which the lacrymal gland 
is very small and situate at the posterior angle 
of the eye, and Mammalia, the secreting ca- 
nals of the lacrymal gland are regularly 
branched and terminate in each acinus in a 
number of small cells. In birds these cells 
are very large; and in them, and likewise in 
the horse, the cells can be filled with mercury 
from the efferent duct. 
Efferent or excretory ducts of the lacrymal 
glands.—The lacrymal glands pour out their 
secretion by nine. or twelve very slender excre- 
tory ducts which proceed from above down- 
wards and open on the surface of the con- 
junctiva on the inside of the upper eyelid. 
The orifices of the ducts are placed at about 
one-twentieth of an inch apart from each other 
in a row extend\gg about half an inch from the 
outer canthus inwards, parallel to but a little 
above the outer part of the upper margin of 
the tarsal cartilage, that is, at the inferior boun- 
dary of the lower mass of the gland. 
The excretory ducts of the lacrymal gland 
were first discovered on the 11th of November, 
1665, by Nicolaus Steno,* in the eyelid of a 
sheep. He delineated them from the eye of 
the calf. Moreover it appears that Steno de- 
scribes vasa lacrymalia discovered in man, 
which opened in the membrane of the upper 
eyelid. 
Admitted by some and doubted by others 
from the time of Steno, the ducts of the lacry- 
mal gland became a subject of dispute between 
Dr. William Hunter{ and the second Monro,§ 
the one claiming to have observed them in the 
human eye before the other. 
The best way to demonstrate the ducts is to 
stretch the upper eyelid, turned inside out, 
upon the finger; then wipe clean the surface 
of the conjunctiva, and having by close in- 
spection at the place where the ducts open, 
as above described, discovered the orifices, 
take a short piece of human hair in the point 
of a forceps, and entering it at the orifice, 
push it on in the direction of the duct. From 
the orifices on the surface of the conjunctiva 
the ducts run nearly parallel with each other 
upwards. 
Of two eyes before me I have in this way 
inserted hairs into nine orifices of ducts in the 
one and into twelve orifices of the other, a 
work which did not occupy five minutes for 
each eye. In both eyes there is one orifice of 
a duct exactly within the external commissure, 
* Observationes Anatomice, quibus varia oris, 
oculorum et narium vasa describuntur, novique 
salive, lacrumarum et muci fontes deteguntur et 
novum Bilsii commentum rejicitur. Leide, 1662. 
See also Bibl. Anat. Clerici et Mangeti. Genev. 
1699. fol. tom. ii. p. 787. 
+ Thom. Bartholoni epistolarum medicinalium a 
doctis et ad doctos scriptarum centuria iii. & iv. 
Hafniez, 1667-8. Epist. 53. cent. iv. 
$ Monro’s Observations, Anatomical and Phy-_ 
siological, wherein Dr. Hunter’s claim to some 
discoveries is examined, p- 77. Edinburgh, 1758. 
§ Dr. William Hunter’s Medical Commentaries, 
p- 1, containing a plain answer to Professor Monro, 
London, 1762-4. 
