These are elongated more or less compound 
_ follicles, secreting a peculiar sebaceous matter 
“intended as an ointment to protect the delicate 
gument of the margins of the eyelids from 
“any irritation which might result from friction, 
or the frequent contact of the tears, and also to 
eserve to it that peculiar degree of sensibility 
which, like all other transition structures from 
skin to mucous membrane, it possesses. The 
Meibomian glands lie imbedded in the sub- 
tance of the tarsal cartilages. They are ar- 
fanged close and parallel to each other, and ge- 
erally speaking in a direction at right angles to 
he ciliary margin of the eyelids, where they open 
that row of minute apertures already mention- 
d. There are between thirty and forty Meibomian 
ands in the upper eyelid, but not so many in 
1 lower, in which also they are shorter in 
onsequence of the difference in breadth be- 
veen the upper and lower tarsus. Sometimes 
> glands are united towards their orifice; 
jometimes, on the other hand, at their end. 
requently the tail of the gland bends laterally 
nd describes an arch. The structure of the 
feibomian glands consists essentially in a 
tral canal running from one extremity to the 
er, like the duct of the pancreas, and around 
that canal glandular loculi or crypte opening 
Into it directly, or through the medium of each 
} The duct suddenly contracts before 
jpening on the margin of the eyelid. In a 
transverse section of the Meibomian glands this 
f is seen, according to Zeiss, as a small 
hole around which are placed from five to six 
glandular grains. 
_ The Meibomian glands of the sow are small ; 
‘Tepresenting merely a short cyst subdivided 
into several loculi. The glands of the eye- 
ashes in the same animal are, on the contrary, 
arge. The Meibomian glands of the sheep, 
dog, and fox, are long very thick-walled bodies, 
im the middle of which there is a wide canal. 
Ranking next in complexity of structure are 
the human Meijbomian glands. Those of the 
horse, ox, goat, and cat; Zeiss found still more 
complex, consisting of lobes, lobules, and 
- granules.* J 
~ The secretion of the Meibomian glands is a 
mild, yellowish, unctuous substance, of the 
tonsistence of lard. Occasionally the external 
orifice of one or more of the Meibomian ducts 
_ becomes covered by a thin film, apparently of 
pidermis. This prevents the escape of the 
cretion, which accumulating raises up the 
' film into a small elevation, like a phlyctenula. 
this does not actually cause pain, but gives 
ise to uneasiness in the part when the eyelids 
re moved: the film is easily broken, and the 
cumulated secretion removed on the point of 
___ Hordeolum, or stye, according to some, is 
abscess of the Meibomian glands ; according 
to others, a small boil implicating the cellular 
tissue at the margin of the eyelid. Zeiss} sus- 
ects it has its seat in the capsule and glands 
__ * Zeiss’s papers in Ammon’s Zeitschrift, B. iv. 
and v., already quoted. 
IS + Locis citans. | 
+3] 
LACRYMAL ORGANS. 
83 
of the roots of the eyelashes. Abscess of the 
Meibomian glands does occur, and gives rise 
to a tumour on the edge of the eyelid like a 
stye, but the nature of the case is seen on 
everting the eyelid. There can be no doubt 
that the roots of the eyelashes are involved in 
the disease, because the hairs at the part affect- 
ed generally fall out at the end. Dr. Zeiss 
proposes to anticipate this result by plucking 
them out at once, and he says that by this pro- 
cedure the progress of the complaint is arrested, 
a thing, certainly, occasionally very desirable. 
In a small inflammatory tumour at the root of 
a hair on the cheek, I have obtained such a 
result from plucking out the hair. 
Fig. 12. 
The eyelids of the right side seen from within. 
( Modified from Soemmerring. ) 
a,a, Inner surface of orbicularis palpebrarum 
muscle. 
b, Palpebral fissure. 
c, c, c, Upper mass of lacrymal gland. 
d, Lower mass of lacrymal gland. . , 
e, e, Conjunctiva. The palpebral portion is 
smoothly spread on the inner surface of the eyelids. 
The portion which has been dissected from off the 
eyeball is in folds. J 
Ff, Hairs inserted into the orifices of the ducts of 
the lacrymal gland. These orifices are on the 
conjunctival surface of the upper eyelids towards 
its temporal extremity. : 
9> gs Meibomian glands of both eyelids seen 
shining through the conjunctiva and the thin layer 
of tarsal cartilage covering them on the inside of 
the eyelids. : 
h, Lacrymal papilla and point of the upper 
eyelid. i 
i, The same of the lower eyelid. 
k, Lacrymal caruncle. : 
l, Semilunar fold pressed aside to show the 
caruncle. 
II. The conjunctiva, semilunar fold, and 
lacrymal caruncle. 
The conjunctiva in general.—Tunica con- 
junctiva seu adnata. Fr. La Conjonctive. 
Ital. La Congiuntiva. Germ. Die Bindhaut. 
The conjunctiva is that membrane which lines 
the posterior surface of the eyelids, and covers 
the front of the eyeball to the extent of about a 
third of its whole periphery. This disposition 
has given rise to the distinction of a palpebral 
and ocular conjunctiva. Towards the margin 
of the orbit, all round the circumference of the 
eyeball, a cul-de-sac is formed by - reflection 
G 
