which it terminates just within the nymphae
and externally to the hymen. The orifice of
the duct (d) is covered by a falciform fold of
mucous membrane, which renders its discovery
sometimes difficult.

This gland secretes a viscid fluid resembling
somewhat the prostatic fluid and having a pe-
culiar odour. Under excitement its secretion
is rapidly formed and, like the contents of the
salivary duct, is sometimes emitted in a jet.
This gland is probably homologous with Cow-
per's gland in the male. In infancy and early
life it is very small, attaining its full develop-
ment in the adult, and again diminishing and
even disappearing in old age.

When the labia and nymphae are abscised
a series of vascular erectile structures are
brought into view, which, together with a
special muscle, surround the vaginal orifice.
These are the vestibular bulb, pars intermedia,
and constrictor vaginae muscle.

Pars intermedia. From the dorsal vein of
the clitoris (fig. 481. d) several branches (n,n)
pass downwards round the sides of the organ
to communicate with a double row of closely-
set venous canals, which commencing ante-
riorly at the glans extend backwards to the
root of the clitoris in the form of a frill that
completely occupies the angle contained in the
curvature of the organ (fig- 481. m and fig.
482. /). These venous canals enter the body
of the clitoris by a double row of apertures
along its under surface. They represent the
communicating veins between the corpus
spongiosum urethras and the corpora caver*-
nosa penis. After receiving branches from
the glans clitoridis (fig. 481. /), nymphae (r),
and labia (/;), they form on either side a
series of convoluted veins (), which spread-
ing downwards and outwards ultimately termi-
nate below in the bulb of the vestibule (fig.
482. and 483. ). This is the structure
termed by Kobelt the pars intermedia. It
corresponds with the corpus spongiosum ure-
thrae of the male, which in the female remains
divided into two halves. The arteries of this



Fig. 482.




Lateral view of the forepart of the pelvis, attached to
which are the clitoris and the vascular and erectile
structures connected with it. (After Kobelt.)

a, vestibular bulb of the left side ; b, veins passing
off from the lower and posterior border of the bulb,
to the pudendal vein ; c, similar veins communica-
ting with the hamiorrhoidal ; c', the spot at which
the veins of the vestibular bulb pass off to the
vagina ; d, pars intermedia ; e, glans clitoridis ; f,
ascending communicating veins proceeding to the
body of the clitoris ; g and i, lateral communicating
branches between the vena dorsalis clitoridis and
pars intermedia ; h, vena dorsalis ; k, bend of the
clitoris ; I, crus clitoridis ; n, vulvo-vaginal gland.

structure (fig. 481. </) are derived from the
pudendal.

Bulbus vestibuli (Kobelt). Plexus retiformis
v. reticularis (De Graaf). Crura clitoridis in-
terna (Swammerdam). Plexus cavernosus
(Tabarranus). Corpus cavernosum (Santorini).
Semibulb (Taylor). Bidb of the vagina.
Lying one on either side of the entrance to the
vagina, and behind the nymphae and labia, are
two masses of vascular parenchyma, composed
almost entirely of tortuous veins enclosed in
a fibrous membrane. These in their collapsed
state are of the size and form of an almond ;
but when injected may be compared to a filled
leech (fig. 482. and 483. ). Anteriorly they
are directly continuous with the structures
last described, while from their sides commu-
nicating branches pass back to the obturator
veins (fig. 483. /), and from their lower ends
to the pudendal and hasrnorrhoidal veins (fig.
482. b and c). The bulb of the vagina, now
commonly regarded as the homotype of the
bulb of the urethra which is here bipartite,
forms the principal portion of the erectile tis-
sue surrounding the vaginal orifice.

Constrictor vaginae. The clitoris together
with its bipartite pars intermedia and vestibu-
lar bulb is encased in a thin sheet of mus-



EXTERNAL ORGANS OF GENERATION.



713



cular structure (fig. 483. b and e), which has
been usually regarded as the constrictor of
the vaginal orifice, but which Kobelt considers
to be more particularly employed as a com-
pressor of the parts just named. This muscle
takes its origin in a broad flattened base (b)
from the perineal fascia midway between the
anus and tuber ischii. The inner fibres inter-
lace with those of the sphincter ani, while the
outer ones reach to the corresponding ascend-
ing ischial ramus. Thence the muscle be-
comes gradually smaller as it ascends, and after
embracing the entire length and breadth of
the vestibular bulb, it converges forwards to
meet its fellow at the clitoris, where it termi-



nates in two little flattened portions of which
the posterior passes as a narrow tendon (fig.
483. d) to unite with its fellow between the
upper end of the bulb and the root of the
clitoris, while the anterior looser portion (c)
mounts over the dorsum of the clitoris, form-
ing the musculus attrahens clitoridis. This
serves to depress the organ and compress
the dorsal vein, at the same time that the
lower portion of the same muscle, by com-
pressing the rest of the vascular apparatus,
forces the blood out of the vestibular bulb and
pars intermedia upwards into the body of the
clitoris, and thus aids in producing congestion
and erection of all these parts during coition.



Fig. 483.




Anterior view of the parts represented in Fig. 482. (After Kobelt.)

a, vestibular bulb ; 6, constrictor vaginas muscle, according to Kobelt the compressor of the bulb. It is
here represented as drawn back behind the bulb, which in the natural position is covered by it. c, an-
terior division of the muscle which passes over the body of the clitoris, serving to depress the organ, and
to compress the dorsal vein ; rf, posterior tendinous division of the same muscle ; e, pars intermedia ; f y
glans clitoridis ; g, veins proceeding from the nymphae ; h, dorsal vein of the clitoris ; t, branches com-
municating with the obturator veins; k, branches ascending to the epigastric veins ; /, obturator veins ;
m, corpus clitoridis ; n, crus clitoridis of the left side.



Blood-vessels of the external organs. The
arteries are supplied by the terminal branches
of the internal pudics and from branches of
the femoral.

The pudic sends off two branches : the
first, or lower (superficial perineal branch),
terminates in the labium after supplying the
sphincter vaginae and some of the perineal
muscles. The second, or superior, mounting
along the ischio-pubic rami to the division of
the crura clitoridis, sends off" a branch (artery
of the bulb] to the bulbus vestibuli, and then
separates into two terminal twigs, the one
(profunda branch) entering the cavernous sub-
stance of the clitoris, while the other forms
the dorsal artery of that body (fig. 48 1 . h}.



The femoral supplies the external pudics, two
in number on each side, which arise by a
common trunk or singly from the inner side
of that vessel. The superior of these branches
(superior pudenda externd] arises near the cru-
ral arch and, passing inwards, sends off two
branches, one to the mons veneris and lower
part of the abdominal integuments, the other,
terminating in the labium, sends also twigs to
the nympha and preputium clitoridis. The
inferior branch (inferior pudenda externa),
arising a little below the former, or from the
profunda, passes obliquely towards the labium
in which it terminates, anastomosing also with
the superficial perineal branch of the pudic.

Veins. The veins of the clitoris and the



714



UTERUS AND ITS APPENDAGES.



venous plexuses surrounding the vaginal
orifice, together with their communicating
branches, have been already described. The
external pudic veins, collecting the blood from
the mons veneris and the interior of the labia,
take a course similar to that of the correspond-
ing arteries, and empty themselves into the
saphena.

The lymphatics of the external organs ter-
minate in the inguinal glands.

The nerves. The external parts are abun-
dantly supplied with nerves derived chiefly
from the pudic. The pudic nerve arising from
the lower part of the sacral plexus passes
through the sacro-sciatic foramen and accom-
panying the pudic vessels divides into two
branches.

The inferior, or perineal branch, sends twigs
to the labia, nymphae, and roots of the clitoris,
and then gives off the superficial perineal
branch, which is distributed to the constrictor
muscle of the bulb of the vagina.

The superior, or branch of the clitoris, corre-
sponds with the dorsal nerve of the penis.
Beneath the pubic arch it passes between the
roots of the clitoris and is distributed along
the side of that organ in the manner already
described (fig* 481. z z'). Some of its ramifica-
tions are distributed upon the prepuce and in
the nymphae and upper parts of the labia.

The labium also receives nerves from the
branches of the inferior pudendal nerve, a di-
vision of the small sciatic nerve. These com-
municate with the superficial perineal branches,

ABNORMAL ANATOMY OF THE EXTERNAL
ORGANS.

Labia. The labia, together with the whole
of the external generative organs, may be
deficient, or they may retain through life an
undeveloped or fetal condition, consisting
only of a very narrow fold of integument. In
rarer cases, the labiurn of one side only has
been developed. The labia may, on the other
hand, present the form of a double or even a
triple fold. In cases of deficiency of the lower
part of the abdominal integument and ante-
rior wall of the bladder, with separation of
the pubic symphysis, the labia are imperfectly
formed, and are set wider apart than usual,
inclining somewhat outwards. The labial
commissure is then also deficient. The pos-
terior commissure of the labia may be much
hypertrophied, projecting unusually forward,
and covering more or less the entrance to the
vagina. The labia are occasionally so com-
pletely coherent along the median line, that
the vulvar fissure is obliterated, leaving only
an aperture sufficient for the passage of urine.
This condition is commonly the result of in-
flammation of the vulva in early infancy.

The diseases affecting the tissues of the
labia may be superficially seated, or may in-
volve more or less their entire substance.
The principal superficial affections are erythe-
matous inflammations, often accompanied by
vesicular, chiefly herpetic or eczematous, and
sometimes pustular eruptions ; enlargement



of the follicles, increased secretion, occasion-
ally watery, and in excessive quantity, occur-
ring in combination with a solid oedematous
condition of the part (oozing tumour of the
labium), excoriations, aphthous or specific
(chancrous) ulcers ; and condylomata, espe-
cially of the softer and syphilitic kind. The
deeper seated affections are acute, and chro-
nic inflammation of the fibrous and cellular
tissue ; induration and hypertrophy, some-
times of considerable extent (elephantiasis);
serous infiltration, associated with pregnancy,
or cardiac disease; suppuration producing
large collections of pus within the labium ;
sloughing and gangrene. The veins of the labia
frequently become varicose in multiparae, and
haemorrhagic effusions take place into their
substance. These effusions may be produced
during straining efforts, or by external vio-
lence, but are especially apt to occur during
labour, from pressure of the child's head upon
the veins returning the blood from the venous
plexuses that surround the vaginal orifice,
whereby the latter become over-distended
and ruptured, a considerable interstitial hae-
morrhage often resulting. Cysts enclosing a
glairy fluid, and adventitious growths of a
more solid kind, such as are common to fibrous
and cellular tissue, are not unfrequently found
within the labia. Cancerous degeneration is
more rare, but it may occur, either alone, or
in combination with vaginal or uterine cancer.
The labia may suffer laceration during labour,
from forcible violation of the person, and in
other ways. FLstulae, communicating with the
rectum, and permitting the passage of fcecal
and gaseous fluids, occasionally form in the
labia as sequelae of suppurative processes.
Lastly, these parts are occasionally the seat
of hernia of the intestine, and, more rarely,
of the ovary.

Clitoris. -Entire absence of the clitoris pro-
bably seldom or never occurs alone. But the
clitoris and nymphae may be deficient even
when the labia are present. The clitoris is
sometimes so small that its presence may
escape detection. More often it is of unusual
size, projecting beyond the labia. Such en-
largements, though occasionally occurring
without degeneration of the tissues, are more
commonly the result of inflammatory hyper-
trophy, or are occasioned by profuse condylo-
matous (syphilitic) growths, in which the
prepuce also may be included. The clitoris
is also subject to cancerous degeneration,
sometimes attaining an enormous size.

NymptuB and vestibule. The protrusion of
the nymphae between the labia, which occurs
as a normal condition in infants, is not unfre-
quently observed in adults, when these parts,
exceeding their ordinary dimensions, hang
down below the posterior commissure : their
lower extremities may in rare cases be pro-
longed as far back as the anus. The number
of the nymphae may be increased to two
(Morgagni), or even three pair (Neubauer).
Excessive hypertrophy of the nymphae is
common in certain climates. It may be asso-
ciated with corresponding enlargement of the



PLACENTA (NORMAL ANATOMY).



715



clitoris. The nymphae are subject to the
same inflammatory and specific disease as the
labia, but they more commonly affect the sur-
faces than the substance of these parts, which,
being of a denser texture than the labia, are
not so easily infiltered with the venous, san-
guineous, or purifonn fluids, that readily collect
within the latter.

The morbid conditions of the vestibule con-
sist chiefly in inflammatory hypertrophy of
the vestibular follicles, especially of those
which immediately surround the urethral ori-
fice and line the sides of the ostium vagina?.
They present the appearance of small red gra-
nulations. A more decided spongy vascular
growth often springs from the border of the
urethral orifice, where it forms either a bright
red fringe, or a soft tumour, varying in size
from a pea to a cherry (vascular tumour of
the meatus). The vulvo-vaginal gland and
its duct may be the special seat of blennor-
rhoea, sometimes of an infecting kind. This
may be made to ooze from the orifice of the
duct, by pressure behind the labium.

The most frequent varieties in the condi-
tions of the hymen and ostium vagina have
been already noticed.* The vaginal orifice
may be nearly or completely obstructed by an
adventitious membrane, or by the hymen pre-
ternaturally developed. Some of these states
are congenital, but others are acquired. In
either case, attention is often not called to
them until after the establishment of puberty.
According to their degree, they interfere with
the functions of the vagina, partly or alto-
gether preventing intromission, and rendering
insemination imperfect or impossible. They
impede the exit of the products of conception
and the escape of the menstrual fluid. In
the latter case, when menstruation is esta-
blished, the fluid collects in and dilates the
vagina and cervix uteri, and lastly the body
of the uterus, and even the Fallopian tubes.
Spontaneous rupture of the hymen, or mem-
brane, may then occur, liberating the fluid.

PLACENTA.

The placenta is the organ provided in
each pregnancy for the nutrition and respira-
tion of the foetus. To this it is connected on
its free side by the umbilical cord, while its
opposite or attached surface is united to the
fundus, sides, or lower part of the body of the
uterus by a layer of the decidua. A placenta
exists only in the mammalia and in some of
the cartilaginous fishes. It is composed of
structures derived partly from the ovum and
partly from the uterus. The fetal or embry-
onal portion is not always furnished by the
same portion of the ovum. It is sometimes
constructed from the yolk sac, as in certain
sharks, and the vessels which ramify in it are
then the branches of the omphalo-mesenteric
artery and vein. In other cases, as in the
mammalia, the chorion supplies the fetal
portion, which is here rendered vascular by

* See VAGINA and HYMEN.



the umbilical vessels derived from the allan-
tois. The maternal or uterine portion of the
placenta is furnished by the decidua or lining
membrane of the uterus. These two portions,
viz., the fetal and the maternal, originally dis-
tinct, and, even in their subsequent union, pre-
serving a certain independence, become more
or less closely connected together by interdigi-
tating the one with the other. Their union
may be one of mere contact, the fetal portion
forming numerous projecting vascular folds
which in the form of laminae or tufts, or single
villi, are received into corresponding depres-
sions or sulci, equally vascular, formed in the
lining membrane of the uterus. Or it may
consist in a more intimate conjunction of these
parts, such as takes place in man, where the
decidua or maternal portion forms a lamina
which is spread over and united to the groups
of villi that constitute the fetal portion. In
the former case at the time of parturition the
two portions are separated, the fetal processes
being simply drawn out of the recesses which
contained them without laceration of either of
the tissues. But in the latter, the one part
cannot be expelled without carrying a con-
siderable portion of the other with it.

Form. The mammalian placenta exhibits
numerous varieties of form. In most Rumi-
nants it is composed of numerous detached
placentulae constituting groups or bosses of
vascular villi that project from the surface of
the chorion, and are received into correspond-
ing cotulas upon the inner surface of the uterus.
In the Carnivora the placenta encircles the
foetus in the form of a broad flat belt. In
Pachydermata, Cetacea, and many other fami-
lies, the villi are nearly evenly distributed over
the whole surface of the chorion, so that the
fetus is everywhere surrounded by placenta.
In some Rodentia and Quadrumana the pla-
centa is double.

In man the placenta forms a single discoid
organ, which in its natural position is slightly
convex upon the outer, and concave upon the
inner superficies. Its outline is generally cir-
cular or oval; it is sometimes reniform, cordate,
or more or less triangular. It is rarely bilobed
or multilobed.

Dimensions and weight. The size of the
placenta is exceedingly variable, bearing usually
a certain proportion to the bulk of the child.
A full-sized oval placenta measures 7 7^" in
its shorter, and 8 9" in its longer diameter,
and measures 23 24'' in circumference. The
thickness is generally greatest opposite to the
point of entrance of the funis, where the organ
measures commonly 1 \\"> but it becomes
gradually attenuated towards the margin,
which is slightly rounded, measuring here
only 2 4'" in thickness. The weight of the
placenta ranges from 15 30 oz. or more.

Foetal surface. Upon the fetal surface of
the placenta are observed portions of the
amnion and chorion, together with the root of
the funis and the principal branches of the
umbilical arteries and vein.

Amnion. The amnion (Jig. 484. am) y after
furnishing the outer covering of the funis,



716



UTERUS AND ITS APPENDAGES.



passes off in all directions at the root of the
cord, and spreads in a thin opaline lamina
over the fetal surface of the placenta, to
which it slightly adheres. In some cases,
especially when 'the umbilical vessels divide
before entering the placenta, the amnion has
no attachment at all to the latter. The am-
nion of the placenta does not differ in any
respect from the rest of the amniotic sac, of
which the placental portion constitutes about
one third. Upon its foetal surface is a single
layer of flattened polygonal cells filled with
delicate fat granulations.

Chorion. The same proportion of chorion
as of the amnion, namely, about one third of
the entire superficies, is appropriated to the
placenta. This, however, is not, like the
amnion, simply an apposed membrane. It
enters into the composition of the organ, and
gives strength to it (fig. 484. ch). It sustains
and transmits the branches of the umbilical
vessels (vf), which adhere to, and ramify upon,
its foetal surface, between it and the amnion.
This face of the chorion is united to the amnion
by a thin and easily separable layer of soft
pulpy tissue, constituting a portion of the
tunica media of the ovum, while the reverse
surface, which forms, as it were, the base or
floor of the placenta, bears the numerous tufts
or villi that make up the bulk of this organ.

Fcetal blood-vessels. The blood-vessels of
the placenta which belong to the foetus are
branches of the two umbilical arteries, and
of the single umbilical vein. These, as just
stated, ramify in large trunks over a consider-
able portion of the fetal or under surface of
the placenta, before they penetrate the cho-
rion to gain the interior of the organ. When
the foetal vessels have been injected from the
funis, their course upon this surface of the
placenta is easily traced. Within the root of
the cord, and at a distance of one inch from
its insertion, the two umbilical arteries com-
municate together by a cross branch half an
inch in length. Immediately on reaching the
placental surface, each artery bifurcates, the
branches passing off in opposite directions.
A second bifurcation takes place, in the same
manner, about half or three quarters of an
inch from the first. And lastly, a third, at
distances ranging from one to two and a half
inches. Each of these dichotomous divisions
is at first more or less abrupt and opposite,
the vessels afterwards bending, and taking a
slightly divergent or parallel course, or even
somewhat approximating. After the third
bifurcation, the vessels again divide and sub-
divide, but now at acute angles ; their extre-
mities become lost, when they are reduced to
the size of a crow quill, by dipping down sud-
denly, and passing through the chorion, to
enter the substance of the placenta at dis-
tances varying from an inch to an inch and a
half from its border. A small branch, how-
ever, in continuation, often runs on nearly to
the edge. Lateral branches, of the same size
as the terminal subdivisions, also leave the
main vessels in all parts of their course, and
dip down into the placental substance.



The branches of the veins, about sixteen in
number, which return the blood from the in-
terior of the placenta, emerge from its sub-
stance close to the points of entrance of the
arteries, and take a less tortuous course than
the latter. They, however, accompany these
vessels, but more in the form of radiating
lines, which proceed towards the root of the
funis, passing under the arteries, and ulti-
mately uniting in the single umbilical vein.

The varieties in the form of the placenta
already noticed are apparently dependent upon
certain modifications in the development and
arrangement of these vessels, which are like-
wise very variable, although the same primary
divisions are noticeable in all. In the circular
placenta the root of the cord is inserted into,
or near, the centre. In the oval form it is
attached to the smaller extremity forming the
placenta en raquette. In the reniform and
cordate placenta, the insertion is likewise more
or less lateral. Lastly, when the vessels of
the cord divide before arriving at the surface,
they form the placenta en parasol.

Uterine surface. The reverse or uterine
surface of a placenta which has been sepa-
rated from its attachment, as in natural labour,
is rough, and is divided into numerous rounded
oval or angular portions, termed lobes or co-
tyledons. These vary from half an inch to
an inch and a half in diameter. The whole
of this surface consists of a thin, soft, and
somewhat leathery investment of deciduous
membrane, which dips down in various parts
to form the sulci that separate the cotyledons
from each other. This layer is a portion of
the decidua which, as long as the parts are
in situ, constitutes the boundary between the
placenta and the muscular substance of the
uterus, but which at the time of labour be-
comes split asunder, so that while a portion