82 
and from the lower edge of the palpebral ten- 
don, curvjng at first downwards Lit oaneeshes 
en upwards and outwards, within the lower 
eyelid and along the edge of the orbit, extend- 
ing some way down over the cheek. The part 
of the orbicularis more immediately contained 
within the eyelids, sometimes called the palpe- 
bral and ciliary portions, in contradistinction to 
the outermost fibres, which are without the eye- 
lids, and encircle the base of the orbit, therefore 
called the orbital portion, consists of pale thin 
fibres, of which those at the margin of the eye- 
lids are collected into a considerable fasciculus, 
having interposed between them and the tarsal 
cartilage the roots of the cilia. At the outer 
canthus the upper and lower fibres intercross 
and adhere to the external palpebral ligament. 
That many of the fibres of the orbicularis are 
inserted into and exert their action in a great 
degree on the skin of the eyelids, may be easily 
ascertained in the living person, by observing, 
during the action of closing the eye, the traction 
of the skin of the eyelids towards the nasal can- 
thus. By this traction, the skin, especially in 
the lower eyelid, is very much corrugated. This 
corrugation of the skin of the lower eyelid by 
the action of the orbicularis is greatest right 
over the lower part of the lacrymal sac,—that 
part which we commonly press upon when we 
want to evacuate any accumulation of mucus or 
tears,—that part where abscess of the sac gene- 
rally bursts and leaves a fistulous opening,— 
that part which we open in the operation for so- 
called fistula lacrymalis. This part of the 
lacrymal sac must therefore be immediately 
affected by the contraction of the muscle, and 
the pressure thus produced, together with that 
on the upper blind end of the sac by the supe- 
rior fibres, will promote the transmission of the 
tears and conjunctival mucus into the nasal 
duct. 
The great use of the orbicularis palpebrarum 
is to close the eyelids; but in effecting this it 
acts at a disadvantage, inasmuch as its action 
on the eyelids is not direct, but oblique ; there- 
fore they are brought together only by being 
drawn horizontally inwards, though it is the 
lower eyelid alone which yields to this latter 
movement. We may imitate in some degree 
the mode of action of the orbicularis, but in an 
opposite direction, by pressing the skin imme- 
diately outside the outer canthus, towards the 
seer mt 
vator palpebre superioris muscle.-—This is 
the antagonist of the upper part of the orbicu- 
laris. It is a weak slender muscle, but then it 
has the advantage of exerting its action in a di- 
rect manner. It extends from the bottom of the 
orbit to the superior tarsal cartilage, lying im- 
mediately underneath the roof of the orbit. It 
is the longest of all the muscles of the orbit. 
Thin and triangular, it rises by its apex, which 
is a short tendon, from the upper edge of the 
optic foramen. The fleshy body of the muscle 
gradually increases in breadth as it proceeds 
forwards ; then bending downwards over the 
eyeball, its insertion takes place by a broad thin 
tendinous expansion, the of the triangle, 
into the upper margin and anterior surface of 
_ LACRYMAL ORGANS. 
the superior targal cartilage, being i 
at the same time witb the ed il | 
ment. It is by the action of this muscle tl 
the upper eyelid is drawn up and retract 
within the orbit. ag 
Having thus described the skeleton and 
cles of the eyelids, it remains to consider #l 
investments and appendages. The investm 
of their inner surface, the palpebral conjuncti 
will be described farther on, along with 
rest of the conjunctiva. The skin of the eyel 
lies over the fibres of the orbicularis palpel 
rum. It is very fine and destitute of hairs, 
contains minute sebaceous follicles. The la 
are sometimes, especially in the lower eyel 
enlarged, and give out a morbid secretion, w. 
is hard, and forms those horny excresce 
occasionally met with in old . 
Cellular tissue of the eyelids —The conjut 
tiva investing the inner surface of the tar 
tilages adheres without the intermedium of at 
cellular tissue. The connection between t 
two structures is immediate and intimate, 
the compound membranes called fibro-m 
The rest of the palpebral conjunctiva ac 
by cellular tissue. The palpebral and ci 
portions of the orbicularis muscle are con 
on the one hand to the tarsal cartilages 
other subjacent parts, and on the other to 
superjacent skin, by a laminar cellular tissu 
which, like that in some other parts of t 
body, is not combined with the adi ssi 
Being rather loose, the cellular tissue of | 
eyelids becomes readily infiltrated by effust 
fluids, as in @dema and emphysema. It i 
unfrequently the seat of abscess. it 
Roots of the eyelashes. From the ante 
edge of the free margins of the eyelids, # 
eyelashes spring. They are inserted three 
four deep, especially in the middle. The ¢ 
sules of the bulbs of the eyelashes lie cle 
the tarsal cartilage under the ciliaris muse! 
skin, extending to the depth of about or 
eighth of an inch. One of the operations 
trichiasis is to extirpate the roots of the ey, 
lashes, but it is very difficult to remove the 
all, the oozing of blood is generally so gre 
When the part has healed the operati 
and the case seems doing well, a hair or 
will often be found here and there sprouti 
out again. . 
Connected with the roots of the eyelas 
as with other hairs, are small sebaceous glan 
consisting of minute but distinct lobules 
grains closely surrounding the capsule, ii 
which they send one or more excretory 
‘Maibconion glands. Glandule 
miane s. palpebrarum sebacee ; — Fr. 
glandes de Meibom ;—Ital. Le glandule 
bomiane ; -Germ. Die Meibomschen Dr 
ncorTr 
Tarsa 
7 = 
a 
* Gurlt, Vergleichende Untersuchungen tiber 
Haut des Menschen und der Haussiugethi 
besonders in Beziehung auf die Absonderun 
des Haut-talges und des Schweisses. In 
Archiv, 1835, p. 399. = 
t Zeiss. Fortgesetzte Untersuchungen wi 
Anatomie und Pathologie der A ider v 
E. Zeiss in Dresden. In Ammon’s Zeitschri 
B. 5, p. 216. 
