A N A T O M Y. 6r 
limber tubes, united laterally to each other through the 
greateft part of their length, and fol*id at their two extre¬ 
mities. By their union two external grooves are formed ; 
one on the upper fide, the other on the lower. The lower 
groove is fomething broader than the upper; and it is fill¬ 
ed through its whole length by the urethra , which is the 
third fpongy tube that compofes the penis. It defcends 
from its origin to the under end of the fymphylis pubis; 
then it afcends before the fymphylis to the root of the pe¬ 
nis; and at lad; re-defcends to the point of the glans. 
About a finger’s breadth from this part it joins a cavernous 
fubftance, in fiiape like a pear, which is connected only to 
the lower convex fide of the canal; and, afterwards being 
fplit on each fide, inverts it quite round. This body is 
called the bulb of the urethra, being larger than any other 
part of that canal, and divided interiorly by a very fine 
membranous feptum into two lateral parts; and there¬ 
fore, when it is inflated, it appears to be double, or with 
two heads. The infide of the canal of the urethra is 
lined by a fine membrane, full of capillary blood - veflels; 
and its furface is perforated by a great number of oblong 
holes, or final 1 lacunae of different (izes, the largeft lying 
near the glans. The cavity of the urethra refembles 
nearly that of a final!.writing pen. It is not every where 
round, and towards the glans becomes broader and flatter 
on each fide, efpecially in the glans itfelf, where there is 
a kind of oval or navicular foflula. The integuments 
which cover all thefe parts are three or four in number. 
The principal is named preputium ; the inner furface of 
which is lined with a fine membrane from the opening all 
the way behind the bafis of the glans, that membrane being 
folded from behind', forward,round the glans, coveringvery 
clofely its whole villous furface, as far as the orifice of the 
urethra, w here it joins the membrane which lines the in¬ 
fide of that canal. This proper membrane of the glans, 
and internal membrane of the praeputium, form conjoint¬ 
ly along the flat part of the glans, from its bafis to the 
orifice of the urethra, a membranous duplicature, which, 
like a feptum or mediaftinum, divides this part into two 
lateral portions, and limits the motions of the praeputium; 
for which reafon it is called freeman preeputii. 
Several mufcles are inferted in the parts which we have 
juft deferibed. They are fix in number; two for the cor¬ 
pora cavernofa, two for the urethra, and two common 
mufcles, called tranfverfales. The arteries of thefe parts 
come chiefly from the iliacse internas or hypogaftricas, and 
and the reft from the iliaca; externas or crurales. The 
principal are termed pudicce, of which one is external, the 
other internal. The diftribution of the veins follows near¬ 
ly that of the arteries; but they have more ramifications 
and communications, as in other places. The principal 
vein is that which runs along the whole fuperior groove 
formed by the union of the corpora cavernofa. It palfes 
diredly under the fymphylis of the ofta pubis, between 
the two arteries. It is very large, and often double. The 
nerves of thefe organs come from the lumbaresand facri; 
and they communicate with the fympatheticus maximus, 
and plexus mefenterici. The nerves of the tefticles are 
very fmall. They are formed by the renal and mefenteric 
plexus. They run along the fpermatic cord ; but it is ex¬ 
ceeding difficult to trace them into the tefticle. 
The femen mafeulinum is firft formed in the tefticle, 
and then conveyed by the vafa deferentia into the veficula; 
feminales, being propelled forward by the motion of the 
fucceeding juices in the tefticle ; and perhaps, in forne mea- 
fure, though flowly, by the contraction of the cremafter. 
This fuppofition is confirmed by the numerous lpires and 
convolutions formed by the epidydimis, obrtructing al- 
moft every kind of injection; and by the length of time 
that is required to fill the feminal veficles again, after they 
have been once exhaufted. The liquor brought from the 
tefticles by the vafa deferentia, is yellowifh, thin, and wa¬ 
tery ; but in the veficula feminales it becomes fomewhat 
thicker and higher coloured. It is white in man when it 
lias been mixed with the liquor of the proftate. It has a 
peculiar fmell in each clafs of animals; and it is the hea- 
vieft humour in the human body. In water a part fepa- 
rates into a kind of cuticle, like a cobweb, that fwims in 
the liquid ; the greater part, which is feeniingly of a pulpy 
nature, falls to the bottom. In the femen which is long 
retained by ebafte people, fhining globules mixed with the 
white liquor are eafily to be feen. It has a very great 
quantity of mucus. That the femen is produced from 
the lymph of the blood, and that the chyle is added to the 
lymph, will appear probable from the fudden alacrity to 
venery that happens after eating, and which is lellened by 
falling. It is compounded of the liquor of the tefticles 
and feminal veflels, the former indeed being more evident 
in fome animals, and the coagulable milk of the proftate 
gland. That liquor, however, only fecundates, which is 
generated in the tefticles, as we fee in eunuchs, who, tho’ 
they have the feminal velfels and proftate, are yet barren. 
The feminal fluid is retained in the veficles as long as a 
man neither exercifes venery, nor fports in imaginary 
dreams. It is always a ftimulus to the animal appetite, as 
long as it is there prefent in any quantity. Belides this, 
there is a confiderable ftrong, volatile, and odorous, part, 
of the femen re-abtorbed into the blood, where it produ¬ 
ces wonderful changes as foon as it begins to be formed ; 
fuch as the protrufion of the beard, the covering of pubes, 
a change of the voice and pallions, horns in cattle, &c. 
for thefe changes in the animal are not the eonfequences 
of age, but of the feminal fluid, and are always abfent in 
eunuchs. The courage and vigour of caftrated animals 
are conftantly diminilhed ; and, in like manner, the fierce- 
nefs of their temper, and the ftrong fmell of their whole 
body, are remarkably weakened. And, from the exam¬ 
ple of fome animals, and even of mankind, it appears that 
the irritation of this fluid has occafioned death, by exci¬ 
ting convulfions. A retention of the femen may follow 
from a narrownefs of the excretory dud, a fchirrhoftty of 
the proftate, and other caufes not iufficiently known. 
The quantity of femen expelled at one time from the 
human veficles is but fmall, more efpecially in a man who 
has not long abftained from venery; and it is natural to 
think that the liquor can be but flowly produced from fo 
fmall an artery. Its generation is accelerated by love, by 
the prefence of the beloved woman ; fo that it diftends the 
velfels with a fenfe of pain. Nature herfelf, therefore, 
enjoins venery, both for preferving the human race, and* 
the health of every individual. That it comes from the 
tefticle, is (hewn by difeafes; in which, the vas deferens 
being obftruded, a fvvelling of the tefticle has enfued. 
The veficles are never emptied, except by venereal actions 
and appetites. In order that the femen, which is only in 
a fmall quantity, fltould be projected with a confiderable 
force, it is previoufty mixed with another fluid from the 
proftate. This gland prepares a thick, white, fofr, sream- 
like, liquor, in large quantity, which is poured out at the 
fame time, and from the fame caufes, with the femen it¬ 
felf, into a little channel at each lide of the openings of 
the feminal veficles, where, mixing with the feminal fluid, 
it imparts the white colour and vilcidity which the femen 
poftelfes. 
It was neceflary for the eanal of the urethra to be firm 
and capable of a direct figure, that it might be able to 
throw out the femen with fufficient vigour; and therefore 
a threefold cavernous body furrounds it. Into the caver¬ 
nous body of the urethra, the blood is poured from the 
arteries, w hich come from deep brandies fent off from the 
external haemorrhoidals; the truth of which is demonftra- 
ted by the injection of any kind of fluid, which, being 
urged through the arteries, eafily flows into thole cellular 
fpaces furrounding the urethra. Thefe cells are not na¬ 
turally turgid with blood, becaufe there are veins open, 
and numerous enough in proportion, to receive and re¬ 
turn what is poured in by the arteries; but, if the return 
is impeded by compreffing thofe veins, the blood is "then 
retained within the cellular fpaces, while the arteries con¬ 
tinue to carry it more fwiftly and ftrongly than the, veins 
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