92 
It lies, by its inner and posterior surface, in 
the lacrymal groove, with the periosteum 
of which it is closely incorporated. Its an- 
terior and outer surface, which lies without 
the groove, is immediately covered by a 
strong aponeurosis derived from the upper 
and lower edge of the horizontal tendon of the 
orbicularis muscle, which passes across the la- 
crymal sac a little above the centre. This apo- 
neurosis adheres to the margins of the bony 
Site in which the sac is lodged, and there 
mes continuous with the periosteum. More 
superficially, the anterior and outer surface is 
covered by the muscular fibres of the orbicu- 
laris and by the skin. 
Above the lacrymal sac forms a cul-de-sac or 
blind end,—finis cecus sacci lacrymalis. Be- 
low it passes into the nasal duct. This transi- 
tion is marked by a slight contraction, some- 
times inside, by a circular fold of the mucous 
membrane, of which both are formed. 
At its anterior and outer part, a little below 
its upper blind end, and immediately behind 
the internal palpebral ligament, the lacrymal 
sac receives the canalicules. Overhanging the 
orifices of these there is a small semilunar fold 
of the mucous membrane of the sac.* 
The nasal duct; ductus nasalis; Fr., Le 
canal nasal ; Ital., Il condotto nasale ; Germ., 
Der Nasenkanal, is a laterally compressed 
canal, about three-quarters of an inch in length, 
and readily admitting the passage of a probe 
the fifteenth of an inch thick, continued from the 
lower part of the lacrymal sac. Itruns downwards, 
backwards, and a little outwards in the osseous 
canal already described, of which it is indeed 
nothing but the membraneous lining. The 
nasal duct is more contracted in its middle than 
at either extremity. It opens in the anterior 
and upper part of the lower meatus, at the 
lateral wall of the nasal cavity, and about one 
inch from the entrance of the nostril. Its ori- 
fice, which is overhung by the lower spongy 
bone, is a long fissure, oblique from above 
downwards and from within outwards. The 
obliquity of the orifice of the nasal duct is 
owing to the circumstance that the posterior or 
external wall of the membraneous part of the 
nasal duct descends farther than the osseous 
canal, and forms, by means of the folded pitui- 
tary membrane, a semi-canal, which descends 
in the external wall of the lower meatus, whilst 
the internal wall of the membraneous part of the 
nasal duct is shorter, and terminates where the 
osseous canal stops. 
The lacrymal sac and nasal duct are com- 
posed of a thick soft mucous membrane, which 
must be considered as productive of that of the 
nose. Externally, this mucous membrane is 
united with the periosteum of the osseous sur- 
faces in connection with the lacrymal sac and 
nasal duct, and as far as concerns that part of 
the lacrymal sac not in the osseous groove, by 
the aponeurosis derived from the tendo palpe- 
brarum. 
Internally, the mucous membrane of the la- 
crymal sac and nasal duct forms various small 
* Rosenmiiller, op. cit. § 125. 
LACRYMAL ORGANS. a 
plicee or ruge. Red and villous, it is q 
different from the white and smooth mu 
membrane of the canalicules. Like the j 
tary membrane of the nose, it secretes, in 
healthy state, a clear, mild, fluid mucus. — 
Lacrymal or tensor tarsi muscle —He¢ 
perhaps the proper place to notice a mi 
which was discovered many years ago 
Duverney,* delineated and described by] 
miller+ in 1805, and more recently re des 
by Dr. Horner,t an American anatomist, 
whose name it is now commonly associate 
To get a view of this muscle, Professor 
ner directs us to cut through the eyeli 
separate them from the ball, at the 
canthus ; then turn the lids over the nos 
move the semilunar fold and the conjunctit 
the neighbourhood, with the fatty matter, 1 
the muscle, such as it is represented in th 
lowing description, will be seen. “a 
“The tensor tarsi arises from the post 
superior part of the os unguis, just in ady 
of the vertical suture between the os planum 
the os unguis. Having advanced three lin 
bifurcates ; one bifurcation is inserted a 
the upper lacrymal canalicule, and termi 
at its punctum, or near it; and the lower b 
cation has the same relation to the lower 
mal canalicule. The base of the laer 
caruncle is placed in the angle of the bifurea 
The superior and the inferior margins of 
muscle touch the corresponding fibres of 
orbicularis palpebrarum, where the latte 
connected with the margin of the internal 
thus of the eye, but may be readily di 
guished by their horizontal course. The 
face of this muscle adheres very closely to 
portion of the sac which it covers, oe als 
the lacrymal canalicules. The lacrymal 
rises about a line above its superior margin, 
extends in the orbit four lines below its infe 
margin. The orbital face of the muse 
covered by a lamina of cellular membrane, 
between this lamina and the ball of the eye 
placed the semilunar fold of the conjun 
and a considerable quantity of adipose ma 
As the bifurcated extremities of the musel 
low the course of the canalicules, they are 
vered by the conjunctiva. The muscle i 
oblong body, half an inch in length, and a 
one quarter wide, bifurcated at one end; ai 
arises much deeper from the orbit than am) 
knowledged origin of the orbicularis. é 
i 
* Cuvres Anatomiques de M. Duverney, to 
4to., Paris, 1761. After speaking of the fib 
the orbicularis which lie over the lacrymal si 
said (tom. i. p. 130), “« Entre ces fibres, il ; 
petit muscle au dédans du grand angle qui) 
son origine de la partie anterieure de 1’os pla 
et s’insere a la partie interne du tendon mitoys 
commun 4 l’apposé de l’orbiculaire; c’est un 
muscle que j’ai observé il y a long-temps.” 
+t Rosenmiiller, Icones Chirurgico-An 
Wiemar, 1805. See also Mackenzie in 
Gazette, vol. xi, 
t Medical Repository for July, 1822. 
A Treatise on Special and General . 
William E. Horner, M. D., Professor of An 
in the University of Pennsylvania, &c, vol. 
498. Philadelphia, 1826. itn 
ra 
