922 
or do exert much influence in supporting the 
weight of the column of feces within the intes- 
tine, or in obstructing the progress of instru- 
ments through it, may be very fairly questioned ; 
for when the rectum has been removed from 
the dead subject and laid open, these valves 
are in general no longer visible, and the natural 
curvatures of the bowel explain sufficiently the 
difficulties encountered in the introduction of 
rectal tubes or bougies in the living. 
Bladder, vesicule seminales, and vasa defe- 
rentia.—It is here necessary to notice briefly so 
much of the under surface of the bladder as is 
uncovered by peritoneum, and to consider in 
a cursory manner the vesicule seminales and 
vasa deferentia. These structures are situated 
very deeply in the perineum, and therefore they 
are dissected with advantage from within the 
Ivis, 
On looking down into the pelvic cavity in a 
recent subject after the peritoneum has been 
displaced and the bladder drawn gently to 
either side, the anatomist obtains a satisfactory 
view of the course and connections of the 
recto-vesical layer of the pelvic fascia, which 
there constitutes the superior boundary of the 
aes The recto-vesical is the innermost 
ayer of the pelvic fascia; after investing the 
inner surface of the levator ani muscle it is 
reflected upon the prostate gland and side of 
the bladder, and more posteriorly upon the 
rectum ; a line drawn from the lower extremity 
of the symphysis pubis to the spinous process 
of the ischium is nearly the level at which this 
reflection takes place. This fascia is closely 
connected in front to the upper surface of the 
prostate gland, and in that situation it forms 
the anterior true ligaments of the bladder; it 
next adheres to the edges of the gland, and 
more posteriorly to the sides of the bladder, 
there constituting the lateral true ligaments of 
that viscus; whilst still further back it is iden- 
tified with the sides of the rectum as has been 
already described. Its attachments to the blad- 
der at either side respectively are situated a 
little above the vesicule seminales. 
This fascia forms the line of demarcation 
between the perineum and the upper portion of 
the pelvic and the abdominal cavity. It is of 
sufficient strength to resist powerfully the des- 
cent of any of the abdominal viscera through 
the space between the bladder and the parietes 
of the pelvis, and affords equal resistance to 
the progress upwards of matter or other effu- 
sions from below; it may be considered as a 
sort of shelving roof to the perineum, and a 
concave floor to the abdomen. Its density and 
strength are at their maximum in front, whilst 
both these properties diminish as it approaches 
the rectum. Above it, is found a quantity of 
loose adipose cellular membrane, continuous 
without line of demarcation with the subserous 
tissue of the abdomen, whilst below it are 
situated the cellular tissue of the perineum and 
the several parts comprised in the depths of 
that region. His knowledge of its connections 
teaches the anatomist that urine effused above 
the level of this fascia must soon reach the 
peritoneum and produce the most disastrous 
PERINEUM. 
consequences ; whilst the experienced surgeon 
endeavours in every operation upon the peri- 
neum to limit his incisions, so as to spare the 
fascia now under consideration. 
That portion of the inferior surface of the 
bladder which projects into the perineum is — 
bounded posteriorly by the peritoneal cul-de- 
sac, and extends forwards as far as the prostate 
gland, whilst the line along which the recto- 
vesical fascia takes attachment to the bladder 
forms its lateral limits. The dimensions of 
this part of the bladder are prance 2 vari- 
able, being modified by the degree of vacuity 
or repletion of the organ itself at the time of 
examination, as well as by the age of the 
individual; but its measurements are al | 
much greater transversely than from before 
backwards. In the adult it is in general of 
moderate extent, but it increases considerably — 
when the urinary reservoir is fully distended, — 
and it diminishes as that viscus becomes empty, 
whilst the variable depth of the cul-de-sac of 
the peritoneum (already dwelt upon in a former 
part of this article) is calculated still further to 
render its size uncertain. In the child this 
region of the bladder scarcely exists, an 
maly explained by the pyriform shape of the 
organ in early life, the narrow neck of 
bladder being then its most dependent portion, 
and the peritoneum being prolonged very 
downwards towards the anus. In old age th 
perineal portion of the bladder often exhil 
extraordinary developement, becoming 
the lowest part of the whole organ, and for 
ing a pouch which projects remarkably to 
the rectum. In many instances calculi becom 
lodged within this depressed part of the vi 
far beneath the level of the cervix vesicx, § 
as to elude detection by the sound ; and in 
manner is explained the valuable assist 
which the finger introduced into the 
so frequently affords the surgeon in orit 
the bladder for a stone. The perineal ic 
of the bladder rests in great measure upon the 
rectum; in the middle line it is in immed 
contact with the gut, but towards either side 
of the vesicula seminalis and vas defere 
1s inte : . 
This region of the bladder has 
special attention from anatomists in ¢ 
quence of its presenting a small trian 
space, in which the operation of recto- 
aracentesis is, or ought to be, perform 
e triangular space in question is ¥ 
small and very nearly equilateral; its b 
rected backwards and upwards, is formed 
the peritoneal cul-de-sac; the vasa defere 
and the vesicule seminales to the bee 
left respectively constitute its sides, whilst 
notch in the prostate gland represents its 
The surgeon ought to consider carefully | 
extent of surface which the area of this trian 
comprises, as well as the average distance fi 
the anus at which it is placed; for should th 
bladder be punctured behind this “pf 
election,” the peritoneum must be 
and should the trocar be introduced in 
it, the prostate gland and common ejacu 
ducts would be endangered, whilst the 
+ 
ag 
VUT 
