layers--an outer one of fibrous, and an inner one of serous structure.
Of these two layers, the abdominal viscera form for themselves a double
envelope. [Footnote] The testis in the loins has a covering from both
membranes, and is still found to be enclosed by both, even when it has
descended to the scrotum. The two coverings of fibro-serous structure
which surrounded the testis in the loins become respectively the tunica
albuginea and tunica vaginalis when the gland occupies the scrotal
cavity.
[Footnote: Langenbeck describes the peritonaeum as consisting of two
layers; one external and fibrous, another internal and serous. By the
first, he means, I presume, that membrane of which the transversalis and
iliac fasciae are parts. (See Comment. de Periton. Structura, &c.) ]
[Illustration: Abdomen and leg, showing blood vessels, muscles
and other internal organs.]
Plate 39--Figure 1
PLATE 39, Fig. 2.--The testicle in the scrotum.--When the testicle, 5,
descends into the scrotum, 7, which happens in general at the time of
birth, the abdomino-scrotal fibro-serous membrane, 6 a, 6 d, is still
continuous at the internal ring, 6 b. From this point downwards, to a
level with the upper border of the testicle, the canal of communication
between the scrotal cavity and the abdomen becomes elongated and
somewhat constricted. At this part, the canal itself consists, like the
abdominal membrane above and the scrotal membrane below, of a fibrous
and serous layer, the latter enclosed within the former. The serous
lining of this canal is destined to be obliterated, while the outer
fibrous membrane is designed to remain in its primitive condition. When
the serous canal contracts and degenerates to the form of a simple cord,
it leaves the fibrous canal still continuous above with the fibrous
membrane (transversalis fascia) of the abdomen, and below with the
fibrous envelope (tunica albuginea) of the testis; and at the adult
period, this fibrous canal is known as the internal spermatic sheath, or
infundibuliform fascia enclosing the remains of the serous canal,
together with the spermatic vessels, &c.
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 39--Figure 2
PLATE 39, Fig. 3.--The serous tunica vaginalis is separated from the
peritonaeum.--When the testicle, 7, has descended to the scrotum, the
serous tube or lining of the inguinal canal and cord, 6 b, 6 c, closes
and degenerates into a simple cord, (infantile spermatic cord,) and
thereby the peritonaeal sac, 6 a, becomes distinct from the serous
tunica vaginalis, 6 d. But the fibrous tube, or outer envelope of the
inguinal canal, remains still pervious, and continues in this condition
throughout life. In the adult, we recognise this fibrous tube as the
infundibuliform fascia of the cord, or as forming the fascia propria of
an external inguinal hernia. The anterior part of the fibrous spermatic
tube descends from the fascia transversalis; the posterior part is
continuous with the fascia iliaca. In relation to the testicle, the
posterior part will be seen to be reflected over the body of the gland
as the tunica albuginea, while the anterior part blends with the
cellular tissue of the front wall of the scrotum. The tunica vaginalis,
6 d, is now traceable as a distinct sac,[Footnote] closed on all sides,
and reflected from the fore part of the testicle, above and below, to
the posterior aspect of the front wall of the scrotum.
[Footnote: Mr. Owen states that the Chimpanzee alone, amongst brute
animals, has the tunica vaginalis as a distinct sac.]
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 39--Figure 3
PLATE 40, Fig. 1.--The abdomino-scrotal serous lining remains continuous
at the internal ring, and a congenital hydrocele is formed.--When the
serous spermatic tube, 6 b, 6 c, remains pervious and continuous above
with the peritonaeum, 6 a, and below with the serous tunica vaginalis, 6
d, the serous fluid of the abdomen will naturally gravitate to the most
depending part--viz., the tunica vaginalis; and thus a hydrocele is
formed. This kind of hydrocele is named congenital, owing to the
circumstance that the natural process of obliteration, by which the
peritonaeum becomes separated from the tunica vaginalis, has been, from
some cause, arrested. [Footnote 1] As long as the canal of
communication, 6 b, 6 c, between the tunica vaginalis, 6 d, and the
peritonaeum 6 a, remains pervious, which it may be throughout life, this
form of hydrocele is, of course, liable to occur. It may be diagnosed
from diseased enlargements of the testicle, by its transparency, its
fluctuation, and its smooth, uniform fulness and shape, besides its
being of less weight than a diseased testis of the same size would be.
It may be distinguished from the common form of hydrocele of the
isolated tunica vaginalis by the fact, that pressure made on the scrotum
will cause the fluid to pass freely into the general cavity of the
peritonaeum. As the fluid distends the tunica vaginalis, 6 c, 6 d, in
front of the testis, this organ will of course lie towards the back of
the scrotum, and therefore, if it be found necessary to evacuate the
fluid, the puncture may be made with most safety in front of the
scrotum. If ascites should form in an adult in whom the tunica vaginalis
still communicates with the peritonaeal sac, the fluid which accumulates
in the latter membrane will also distend the former, and all the
collected fluid may be evacuated by tapping the scrotum. When a
hydrocele is found to be congenital, it must be at once obvious that to
inject irritating fluids into the tunica vaginalis (the radical cure) is
inadmissible. In an adult, free from all structural disease, and in whom
a congenital hydrocele is occasioned by the gravitation of the ordinary
serous secretion of the peritonaeum, a cure may be effected by causing
the obliteration of the serous spermatic canal by the pressure of a
truss. When a congenital hydrocele happens in an infant in whom the
testicle, 5, Fig. 1, Plate 39, is arrested in the inguinal canal,
[Footnote 2] if pressure be made on this passage with a view of causing
its closure, the testicle will be prevented from descending.
[Footnote 1: The serous spermatic tube remains open in all quadrupeds;
but their natural prone position renders them secure against hydrocele
or hernial protrusion. It is interesting to notice how in man, and the
most anthropo-morphous animals, where the erect position would subject
these to the frequent accident of hydrocele or hernia, nature causes the
serous spermatic tube to close.]
[Footnote 2: In many quadrupeds (the Rodentia and Monotremes) the testes
remain within the abdomen. In the Elephant, the testes always occupy
their original position beneath the kidneys, in the loins. Human adults
are occasionally found to be "testi-conde;" the testes being situated
below the kidneys, or at some part between this position and the
internal inguinal ring. Sometimes only one of the testes descends to the
scrotum.]
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 40--Figure 1.
PLATE 40, Fig. 2.--The serous spermatic canal closes imperfectly, so as
to become sacculated, and thus a hydrocele of the cord is formed.--After
the testicle, 7, has descended to the scrotum, the sides of the serous
tube, or lining of the inguinal canal and cord, 6 b, 6 c, may become
adherent at intervals; and the intervening sacs of serous membrane
continuing to secrete their proper fluid, will occasion a hydrocele of
the cord. This form of hydrocele will differ according to the varieties
in the manner of closure; and these may take place in the following
modes:--1st, if the serous tube close only at the internal ring, 6 a,
while the lower part of it, 6 b, 6 c, remains pervious, and
communicating with the tunica vaginalis, 6 d, a hydrocele will be formed
of a corresponding shape; 2nd, if the tube close at the upper part of
the testicle, 6 c, thus isolating the tunica vaginalis, 6 d, while the
upper part, 6 b, remains pervious, and the internal ring, 6 a, open, and
communicating with the peritonaeal sac, a hydrocele of the cord will
happen distinct from the tunica vaginalis; or this latter may be, at the
same time, distended with fluid, if the disposition of the subject be
favourable to the formation of dropsy; 3rd, the serous tube may close at
the internal ring, form sacculi along the cord, and close again at the
top of the testicle, thus separating the tunica vaginalis from the
abdomen, and thereby several isolated hydroceles may be formed. If in
this condition of the parts we puncture one of the sacs for the
evacuation of its contents, the others, owing to their separation, will
remain distended.
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 40--Figure 2.
PLATE 40, Fig. 3.--Hydrocele of the isolated tunica vaginalis.--When the
serous spermatic tube, 6 b, 6 c, becomes obliterated, according to the
normal rule, after the descent of the testicle, 7, the tunica vaginalis,
6 d, is then a distinct serous sac. If a hydrocele form in this sac, it
may be distinguished from the congenital variety by its remaining
undiminished in bulk when the subject assumes the horizontal position,
or when pressure is made on the tumour, for its contents cannot now be
forced into the abdomen. The testicle, 7, holds the same position in
this as it does in the congenital hydrocele. [Footnote] The radical cure
may be performed here without endangering the peritonaeal sac.
Congenital hydrocele is of a cylindrical shape; and this is mentioned as
distinguishing it from isolated hydrocele of the tunica vaginalis, which
is pyriform; but this mark will fail when the cord is at the same time
distended, as it may be, in the latter form of the complaint.
[Footnote: When a hydrocele is interposed between the eye and a strong
light, the testis appears as an opaque body at the back of the tunica
vaginalis. But this position of the organ is, from several causes,
liable to vary. The testis may have become morbidly adherent to the
front wall of the serous sac, in which case the hydrocele will distend
the sac laterally. Or the testis may be so transposed in the scrotum,
that, whilst the gland occupies its front part, the distended tunica
vaginalis is turned behind. The tunica vaginalis, like the serous
spermatic tube, may, in consequence of inflammatory fibrinous effusion,
become sacculated-multilocular, in which case, if a hydrocele form, the
position of the testis will vary accordingly.--See Sir Astley Cooper's
work, ("Anatomy and Diseases of the Testis;") Morton's "Surgical
Anatomy;" Mr. Curling's "Treatise on Diseases of the Testis;" and also
his article "Testicle," in the Cyclopaedia of Anatomy and Physiology.]
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 40--Figure 3.
PLATE 40, Fig. 4.--The serous spermatic tube remaining pervious, a
congenital hernia is formed.--When the testicle, 7, has descended to the
scrotum, if the communication between the peritonaeum, 6 a, and the
tunica vaginalis, 6 c, be not obliterated, a fold of the intestine, 13,
will follow the testicle, and occupy the cavity of the tunica vaginalis,
6 d. In this form of hernia (hernia tunicae vaginalis, Cooper), the
intestine is in front of, and in immediate contact with, the testicle.
The intestine may descend lower than the testicle, and envelope this
organ so completely as to render its position very obscure to the touch.
This form of hernia is named congenital, since it occurs in the same
condition of the parts as is found in congenital hydrocele--viz., the
inguinal ring remaining unclosed. It may occur at any period of life, so
long as the original congenital defect remains. It may be distinguished
from hydrocele by its want of transparency and fluctuation. The impulse
which is communicated to the hand applied to the scrotum of a person
affected with scrotal hernia, when he is made to cough, is also felt in
the case of congenital hydrocele. But in hydrocele of the separate
tunica vaginalis, such impulse is not perceived. Congenital hernia and
hydrocele may co-exist; and, in this case, the diagnostic signs which
are proper to each, when occurring separately, will be so mingled as to
render the precise nature of the case obscure.
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 40--Figure 4.
PLATE 40, Fig. 5.--Infantile hernia.--When the serous spermatic tube
becomes merely closed, or obliterated at the inguinal ring, 6 b, the
lower part of it, 6 c, is pervious, and communicating with the tunica
vaginalis, 6 d. In consequence of the closure of the tube at the
inguinal ring, if a hernia now occur, it cannot enter the tunica
vaginalis, and come into actual contact with the testicle. The hernia,
13, therefore, when about to force the peritonaeum, 6 a, near the closed
ring, 6 b, takes a distinct sac or investment from this membrane. This
hernial sac, 6 e, will vary as to its position in regard to the tunica
vaginalis, 6 d, according to the place whereat it dilates the
peritonaeum at the ring. The peculiarity of this hernia, as
distinguished from the congenital form, is owing to the scrotum
containing two sacs,--the tunica vaginalis and the proper sac of the
hernia; whereas, in the congenital variety, the tunica vaginalis itself
becomes the hernial sac by a direct reception of the naked intestine. If
in infantile hernia a hydrocele should form in the tunica vaginalis, the
fluid will also distend the pervious serous spermatic tube, 6 c, as far
up as the closed internal ring, 6 b, and will thus invest and obscure
the descending herniary sac, 13. This form of hernia is named infantile
(Hey), owing to the congenital defect in that process, whereby the
serous tube lining the cord is normally obliterated. Such a form of
hernia may occur at the adult age for the first time, but it is still
the consequence of original default.
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 40--Figure 5.
PLATE 40, Fig. 6.--Oblique inguinal hernia in the adult.--This variety
of hernia occurs not in consequence of any congenital defect, except
inasmuch as the natural weakness of the inguinal wall opposite the
internal ring may be attributed to this cause. The serous spermatic tube
has been normally obliterated for its whole length between the internal
ring and the tunica vaginalis; but the fibrous tube, or spermatic
fascia, is open at the internal ring where it joins the transversalis
fascia, and remains pervious as far down as the testicle. The intestine,
13, forces and distends the upper end of the closed serous tube; and as
this is now wholly obliterated, the herniary sac, 6 c, derived anew from
the inguinal peritonaeum, enters the fibrous tube, or sheath of the
cord, and descends it as far as the tunica vaginalis, 6 d, but does not
enter this sac, as it is already closed. When we compare this hernia,
Fig. 6, Plate 40, with the infantile variety, Fig. 5, Plate 40, we find
that they agree in so far as the intestinal sac is distinct from the
tunica vaginalis; whereas the difference between them is caused by the
fact of the serous cord remaining in part pervious in the infantile
hernia; and on comparing Fig. 6, Plate 40, with the congenital variety,
Fig. 4, Plate 40, we see that the intestine has acquired a new sac in
the former, whereas, in the latter, the intestine has entered the tunica
vaginalis. The variable position of the testicle in Figs. 4, 5, & 6,
Plate 40, is owing to the variety in the anatomical circumstances under
which these herniae have happened.
[Illustration: Abdomen and scrotum, showing bone, blood vessels
and other internal organs.]
Plate 40--Figure 6.
COMMENTARY ON PLATES 41 & 42.
DEMONSTRATIONS OF THE ORIGIN AND PROGRESS OF INGUINAL HERNIAE IN GENERAL.
PLATE 41, Fig. 1.--When the serous spermatic tube is obliterated for its
whole length between the internal ring, 1, and the top of the testicle,
13, a hernia, in order to enter the inguinal canal, 1, 4, must either
rupture the peritonaeum at the point 1, or dilate this membrane before
it in the form of a sac. [Footnote] If the peritonaeum at the point 1 be
ruptured by the intestine, this latter will enter the fibrous spermatic
tube, 2, 3, and will pass along this tube devoid of the serous sac. If,
on the other hand, the intestine dilates the serous membrane at the
point, 1, where it stretches across the internal ring, it will, on
entering the fibrous tube, (infundibuliform fascia,) be found invested
by a sac of the peritonaeum, which it dilates and pouches before itself.
As the epigastric artery, 9, bends in general along the internal border
of the ring of the fibrous tube, 2, 2, the neck of the hernial sac which
enters the ring at a point external to the artery must be external to
it, and remain so despite all further changes in the form, position, and
dimensions of the hernia. And as this hernia enters the ring at a point
anterior to the spermatic vessels, its neck must be anterior to them.
Again, if the bowel be invested by a serous sac, formed of the
peritonaeum at the point 1, the neck of such sac must intervene between
the protruding bowel and the epigastric and spermatic vessels. But if
the intestine enter the ring of the fibrous tube, 2, 2, by having
ruptured the peritonaeum at the point 1, then the naked intestine will
lie in immediate contact with these vessels.
[Footnote: Mr. Lawrence (op. cit.) remarks, "When we consider the
texture of the peritonaeum, and the mode of its connexion to the
abdominal parietes, we cannot fancy the possibility of tearing the
membrane by any attitude or motion." Cloquet and Scarpa have also
expressed themselves to the effect, that the peritonaeum suffers a
gradual distention before the protruding bowel.]
[Illustration: Abdomen, showing bone, blood vessels
and other internal organs.]
Plate 41--Figure 1
PLATE 41, Fig. 2--When the serous spermatic tube, 11, remains pervious
between the internal ring, 1, (where it communicates with the general
peritonaeal membrane,) and the top of the testicle, (where it opens into
the tunica vaginalis,) the bowel enters this tube directly, without a
rupture of the peritonaeum at the point 1. This tube, therefore, becomes
one of the investments of the bowel. It is the serous sac, not formed by
the protruding bowel, but one already open to receive the bowel. This is
the condition necessary to the formation of congenital hernia. This
hernia must be one of the external oblique variety, because it enters
the open abdominal end of the infantile serous spermatic tube, which is
always external to the epigastric artery. Its position in regard to the
spermatic vessels is the same as that noticed in Fig, 1, Plate 41. But,
as the serous tube through which the congenital hernia descends, still
communicates with the tunica vaginalis, so will this form of hernia
enter this tunic, and thereby become different to all other herniae,
forasmuch as it will lie in immediate contact with the testicle.
[Footnote]
[Footnote: A hernia may be truly congenital, and yet the intestine may
not enter the tunica vaginalis. Thus, if the serous spermatic tube close
only at the top of the testicle, the bowel which traverses the open
internal inguinal ring and pervious tube will not enter the tunica
vaginalis.]
[Illustration: Abdomen, showing bone, blood vessels
and other internal organs.]
Plate 41--Figure 2
PLATE 41, Fig. 3.--The infantile serous spermatic tube, 11, sometimes
remains pervious in the neighbourhood of the internal ring, 1, and a
narrow tapering process of the tube (the canal of Nuck) descends within
the fibrous tube, 2, 3, and lies in front of the spermatic vessels and
epigastric artery. Before this tube reaches the testicle, it degenerates
into a mere filament, and thus the tunica vaginalis has become separated
from it as a distinct sac. When the bowel enters the open abdominal end
of the serous tube, this latter becomes the hernial sac. It is not
possible to distinguish by any special character a hernia of this
nature, when already formed, from one which occurs in the condition of
parts proper to Fig. 1, Plate 41, or that which is described in the note
to Fig. 2, Plate 41; for when the intestine dilates the tube, 11, into
the form of a sac, this latter assumes the exact shape of the sac, as
noticed in Fig. 1, Plate 41. The hernia in question cannot enter the
tunica vaginalis. Its position in regard to the epigastric and spermatic
vessels is the same as that mentioned above.
[Illustration: Abdomen, showing bone, blood vessels
and other internal organs.]
Plate 41--Figure 3
PLATE 41, Fig. 4.--If the serous spermatic tube, 11, be obliterated or
closed at the internal ring, 1, thus cutting off communication with the
general peritonaeal membrane; and if, at the same time, it remain
pervious from this point above to the tunica vaginalis below, then the
herniary bowel, when about to protrude at the point 1, must force and
dilate the peritonaeum, in order to form its sac anew, as stated of Fig.
1, Plate 41. Such a hernia does not enter either the serous tube or the
tunica vaginalis; but progresses from the point 1, in a distinct sac. In
this case, there will be found two sacs--one enclosing the bowel; and
another, consisting of the serous spermatic tube, still continuous with
the tunica vaginalis. This original state of the parts may, however,
suffer modification in two modes: 1st, if the bowel rupture the
peritonaeum at the point 1, it will enter the serous tube 11, and
descend through this into the cavity of the tunica vaginalis, as in the
congenital variety. 2nd, if the bowel rupture the peritonaeum near the
point 1, and does not enter the serous tube 11, nor the tunica
vaginalis, then the bowel will be found devoid of a proper serous sac,
while the serous tube and tunica vaginalis still exist in communication.
In either case, the hernia will hold the same relative position in
regard to the epigastric artery and spermatic vessels, as stated of Fig.
1, Plate 41.
[Illustration: Abdomen, showing bone, blood vessels
and other internal organs.]
Plate 41--Figure 4
PLATE 41, Fig. 5.--Sudden rupture of the peritonaeum at the closed
internal serous ring, 1, though certainly not impossible, may yet be
stated as the exception to the rule in the formation of an external
inguinal hernia. The aphorism, "natura non facit saltus," is here
applicable. When the peritonaeum suffers dilatation at the internal
ring, 1, it advances gradatim and pari passu with the progress of the
protruding bowel, and assumes the form, character, position, and
dimensions of the inverted curved phases, marked 11, 11, till, from
having at first been a very shallow pouch, lying external to the
epigastric artery, 9, it advances through the inguinal canal to the
external ring, 4, and ultimately traverses this aperture, taking the
course of the fibrous tube, 3, down to the testicle in the scrotum.
[Illustration: Abdomen, showing bone, blood vessels
and other internal organs.]
Plate 41--Figure 5
PLATE 41, Fig. 6.--When the bowel dilates the peritonaeum opposite the
internal ring, and carries a production of this membrane before it as
its sac, then the hernia will occupy the inguinal canal, and become
invested by all those structures which form the canal. These structures
are severally infundibuliform processes, so fashioned by the original
descent of the testicle; and, therefore, as the bowel follows the track
of the testicle, it becomes, of course, invested by the selfsame parts
in the selfsame manner. Thus, as the infundibuliform fascia, 2, 3,
contains the hernia and spermatic vessels, so does the cremaster muscle,
extending from the lower margins of the internal oblique and
transversalis, invest them also in an infundibuliform manner. [Footnote]