930 
and the crus penis, posteriorly by the trans- 
versus perinzi, which constitutes the base of the 
triangle, whilst the apex is in front where the 
crus penis and the urethra unite. These spaces 
are small in the natural condition, but when 
carefully dissected they become very distinct ; 
the superficial perineal vessels and nerves 
traverse them from basé to apex ; by separating 
the accelerator uring from the erector penis 
the anatomist obtains a view of the triangular 
ligament of the urethra between these muscles, 
and he may also form some estimate of its 
thickness and strength by the touch. 
When the muscles and other structures be- 
longing to the same layer of parts have been 
removed, the crura penis along the sides of 
the region, the urethra in the centre, and the 
triangular ligament of the urethra stretching 
across the arch of the pubis, are brought fairly 
into view; still further back, in the middle 
line, the recto-urethral triangular space may 
be partially seen, and also some fibres of the 
levator ani muscle descending to their insertion 
from behind the triangular ligament. 
It is unnecessary in this article to describe 
the crura penis minutely. Each crus adheres to 
the rami of the ischium and pubis, becoming 
gradually thicker and larger as it approaches 
the symphysis, and at length the two crura unite 
to form the body of the penis; the lateral 
margins of the triangular ligament of the ure- 
thra, and the great pudic vessels and nerves in 
the last part of their course, are overlapped by 
the crura as they ascend. 
The anatomy of the urethra in respect to 
catheterism has received the fullest considera- 
tion already, but the position of the bulb may 
be now again studied with advantage. This 
body lies in front of the triangular ligament 
of the urethra, and projects backwards and 
downwards towards the rectum; it is situated 
about one inch from the anus, and scarcely 
more than half that distance from the anterior 
wall of the intestine ; yet the narrow interval 
between the bulb and the rectum constitutes a 
portion of the recto-urethral triangular space, 
through which the early incisions in the bila- 
teral operation of lithotomy are carried. The 
bulb is retained in its position by a thin expan- 
sion derived from the anterior layer of the tri- 
angular ligament, and continuous with the 
membrane which invests the corpus spongio- 
sum urethra. 
The triangular ligament of the urethra (“ the 
deep perineal fascia” of some anatomists, “the 
perineal ligament” of M. Carcassone, “the 
middle perineal aponeurosis” of M. Blandin) 
presents itself next for examination. To expose 
the superficial surface of this ligament it is only 
further necessary to detach the crura penis 
from the bones and to free the bulb from its 
connections, but to exhibit the deeper surface 
satisfactorily the dissection must be conducted 
from within the pelvis. The triangular liga- 
ment of the urethra extends from the rami of 
the ischium and pubis at one side to the cor- 
responding edges of bone on the other; its 
superficial surface, directed forwards and down- 
wards, is in contact (so long as the parts remain 
PERINEUM. 
in situ) with the crura penis, the bulb of the 
urethra, and the muscles already ified ; its 
posterior surface, directed upwards and back- 
wards, is related to the prostate gland, the 
membranous portion of the urethra, Wilson's 
muscles, and ie levatores ani; its base, directed 
downwards and backwards towards the rectum, 
gives attachment to the deep process of the — 
superficial perineal fascia, and presents a 
double curvature, being prolongedin the middle 
line into a peak, which adheres to the central 
tendinous point of the perineum; its ape 
corresponds to the lower extremity of the sym- 
physis pubis, and includes the sub-pubie liga- 
ment between its lamin, whilst its lateral mar- 
gins adhere firmly to the rami of the ischium and — 
pubis, and are distinctly continuous with the 
obturator fascia on either side. The ing 
which affords a e to the urethra is si- 
tuated about half an inch or rather less above — 
the base of this ligament, and nearly one inch 
beneath the symphysis pubis, whilst that which 
transmits the dorsal veins of the penis is placed — 
immediately below the sub-pubic ligament. 
The triangular ligament uncommon | 
strength; it serves to fix and to strengthen the 
urethra and to fill up the arch of the pubis, 
completing the walls of the pelvis where the 
bones are deficient, and thus supporting power 
fully the abdominal and pelvic viscera. It con- 
stitutes a perfect partition between the supe 
ficial and the deep structures in the periney 
dividing the genito-urinary portion of this 
gion into two distinct compartments; and 
consists of two lamine inseparably united te 
each other in some places, not so in others 
for Cowper’s glands, the sub-pubic ligament 
the arteries of the bulb, the interna 
vessels in a part of their course, and 
called muscles of Guthrie, are developed betwee 
its layers. 
Cowper’s glands may be displayed 
easefal wothoral of the cuperficial ye a 
triangular ligament ; they are two small greyis! 
bodies, each resembling a pea in shape and ¢ 
mensions, and placed one on either side | 
hind and above the bulb, beneath the me 
branous portion of the urethra, and between 1 
lamin of the triangular ligament. Their due 
which open into the urethra in front of the 
have been already described. 
Guthrie’s muscles, two in number, are si 
ated (according to their discoverer) between 
layers of the triangular ligament; each of thi 
as described by him, arises narrow and tei 
nous from the descending ramus of the p 
hear its junction with the ischium, and bec 
ing fleshy it passes tranversely inwards, — 
soon divides into two fascicull, of which 
spreads out on the upper surface and the o 
on the lower surface of the memb 
of the urethra. In this manner the mu 
from opposite sides meet in a tendinous 
on the middle line of the urethra both @ 
and below, the superior raphé being prolo 
from the prostate gland to the junction oj 
crura penis, and the inferior raphé exten 
from the prostate to the bulb. Viewed ¢ 
from above or from below, these muscle: 
Ls 
r 
anou: I 
P of 
