ANATOMY. 
6 20 
return it. Thus the ftagnant blood diftends the bulb of 
the urethra, together with its cavernous body, and the 
glans itfelf. This diftenfion is generally performed at the 
fame time, when the other cavernous bodies of the penis, 
with which this of the urethra has no communication, 
are likewife rigidly diffended. 
Thefe cavernous bodies of the penis, having their fpon- 
gy fabric defended in coition by the blood retained by the 
veins, and (till propelled by the arteries, becomes rigidly 
turgid, and fuliain the otherwife flaccid or but weakly 
filled urethra, in fuch a manner that it may be able to con¬ 
duct the femen into the uterus. All this is demonftrated 
from the diffection of brute animals in the aft of venery, 
from an artificial erection, and from the injection, of li¬ 
quid matters into the velfels of the penis. The caufes of 
this ereftion are love; the defire of pleafure; thefriction 
of the glans; various irritations of the bladder, tefticles, 
feminal velfels, and urethra, from the urine, from abun¬ 
dance of good feed, from the venereal poifion* from can- 
tharides, whipping the parts, and, laltly, from convulfion 
of the nerves. The proximate caufe of this diltenlion 
remains ftill to be explained. 
In order to diftend the penis, there mu ft be either a 
comprefl'ure of the vein bringing back the blood from the 
cavernous bodies of the penis or urethra; or at lead it is 
neceffary that there fliould be a conftriition of the fmaller 
veins that every where open within the cavernous bodies, 
to hinder them from abforbing and returning the blood 
from the arteries. The firft, however, may be effected by 
the levator, drawing up the proftate and bladder : but it 
is very probable, that, as we fee in the nipples of the 
breads, in the loofe' pendulous gills of the turkey-cock, 
and in the blufhing or rednefs of the fate from paflions of 
the mind, erection may be produced without the imme¬ 
diate interpolition of any peculiar muPcle. This fuppofi- 
tion is confirmed by brute animals, which all couple with¬ 
out the life of any erector mufcle ; by the erections which 
take place in animals totally different from man, and ef- 
pecially thofe which take place in birds very quickly; and 
by the inactivity of the eredtor mufcles themfelves in the 
libidinous eredtion of the penis, and from their unfitnefs 
for comprelling the veins. It is alfo probable, that an 
eredtion may be produced by the numerous ramifications of 
the nerves exciting a convulfive conftridtion of the veins; 
while, at the fame time, the arteries, by an increafed ve¬ 
locity of the blood, bring more blood to the parts than the 
veins can carry off. The caufe of this convulfion is per¬ 
haps inherent in thefe nervous fphindters themfelves, and 
depends either on a mechanical irritation of the nervous 
fibres, or on the force of the imagination. 
A long-continued and violent eredfion is at laft accom¬ 
panied with an expullion of the femen ; and this requires 
much greater force than is requifite for the ^eredfion only. 
For the femen is expelled when the irritation of the nerves 
is arrived at its greateft height: and in natural venery, 
when, at'length, the cellular fpaces of the urethra and its 
continuous glans, which are at laft filled, become Co far 
diffended with a large quantity of warm blood, that the 
nervous papillae, ftretened out in the latter, become vio¬ 
lently affedled from the irritating or pleafing caufe. 1 lie 
feminal veficles are emptied by the levator mufcles of the 
anus, which prefs them againft the refitting bladder with 
a convulfive motion, excited either by a voluptuous ima¬ 
gination, or by the exquifite fenlibility of the nerves of the 
glans, principally in its lower part, which is in the neigh¬ 
bourhood of the frenum. lienee the femen is never dif- 
churged with any of the urine in an healthy man; becaufe 
the expullion of it requires the blander to be clofed or 
dra\ n up firmly together; for, while lax, it affords little 
or no refiftance ro the feminal veficles. 1 he tranfverfe 
mufcles ieem ’o dffate the canal of the urethra for the re- 
cepti n of the femen expreffed from the veficles. Soon 
affer. ards the powers conftringr.g the urethra are, from 
t'nc irritation ot the very fenfible fabric of that canal, p' t 
into action. To this conftridtion conduces principally the 
accelerator, which makes a powerful concuftionof the bulb 
and adjacent part of the urethra, fo as to propel its contents 
more fwiftly. But that this may aCt firmly, the fphincter 
of the anus, together with that of the bladder, muff be 
well (hut. The accelerator mufcle feems alfo principally 
concerned in the eredtion, by comprelling the veins of the 
corpus cavernofum of the urethra. At the fame time *he 
ereclores penis, as they are called, arifing from the tubercles 
ot the ilchium, becime tenfe, and are mferted into the ca¬ 
vernous bodies, fuff aiding the penis as a fort of medium 
between the tranfverfe and perpendicular direction. Thus 
the femen is driven into the vagina, in a prolific coition : 
the whole action ot which is very impetuous, and comes 
near to a convulfion ; whence, if too often repeated, it won¬ 
derfully weakens the habit, and greatly, injures the whole 
nervous fyftein, as the maladies arifing from thence, in con- 
fequencc of the affection of the nerves, without which 
the femen cannot be expelled, feem to indicate. 
The PARTS of GENE RAT 10 N in FEMALES. 
Thefe are fonre of them external, and dome internal; 
and they are all of them fubordinate to one principal in¬ 
ternal part, called the uterus , or womb. The other internal 
parts are the tubie Fallopiame, ovaria, vafa fpermatica, li- 
gamenta lata, the ropes or bands called ligamenta rotunda, 
and the canal of the uterus. The external parts are the 
pubes, the alae nyrnphte, clitoris, orifice of the urethra, 
and the orifice of the vagina. The uterus lies betw een the 
bladder and the inteftinum rectum. It is a body inwardly 
hollow, outwardly of a whitiffi colour, of a folid fubltance, 
and, except in time of pregnancy, of the figure of a flat 
flatk. The broadeft portion is termed (lie fundus , and the 
narrowed the neck, which terminates at the extremity by a 
tranfverfe opening. This opening is termed the internal 
orifice of the uterus ; and, in the natural date, is fo narrow, 
that only a fmall probe can be palled through it. The 
inner furface of the Cavity of the uterus is lined by a very 
fine membrane, which at the fundus or broad portion is 
fmooth and even; but, in the narrow portion which leads 
to the orifice, it is wrinkled in a particular manner. The 
portion of this membrane, which covers the bottom of 
the cavity, is perforated by a great number of confiderable 
holes, through which fmall drops of blood-may be ob- 
ferved to pafs when the whole uterus is compreffed; and 
fometimes it appears to have very fmall hairs or villi. 
Thefe villi and holes are obf'erved to be more or lefs tin¬ 
ged with blood in women who die in the time of their menfes. 
The uterus is covered by a portion of the peritonaeum, 
which ferves it for a coat, and is the continuation of that 
which covers the bladder and rectum, running up from 
the lower and pofterior part of the bladder, over the ante¬ 
rior part of the uterus, and from thence over the fundus, 
and down the pofterior fide, and afterwards going to the 
refhim. On each lateral part or edge of the uterus this 
portion of the peritonaeum forms a broad duplicature, 
which is extended on each fide, more or lefs direftly to 
the neighbouring lateral parts of the pelvis, forming what 
are termed the broad ligaments. The laminae of thefe du- 
plicatures are connected by a cellular ftibftance; and they 
contain the Fallopian tubes, the ovaria, a part of Hie fper- 
matic velfels, and of thofe that go to the body of the ure- 
rus, the ropes called the round ligaments, the nerves, &c. 
he ovaria are two whitilh, oval, fiat, oblong, bodies, 
(fiuated on the (ides of the fandus uteri, to vvhicli they are 
fixed by a kind of (hort round ligament. They are com- 
pofed of a compaft fpongy lubftance, and of feveral little 
balls, or tranfparent veiiculse, called ova. The Fallopian 
tubes are two flaccid, conical, and vermiform, canals, (filia¬ 
ted more or lefs tranfverlely on each fide of the uterus, 
between the fundus and the lateral parts of the pelvis. 
B ach of'ihem is fixed by its narrow extremities in the cor¬ 
ner of the fundus inert, into which it opens, ’hough by fo 
narrow a duct as hardly to admit a large bridle, ft'rom 
thence their diameter augments by degrees all the way to 
the other extremity, where it is about one-third pari of 
an 
