Chapter 2

and joining--

e e. The saphenous vein.

f. The middle cutaneous nerve, derived from the anterior crural nerve.

g. Femoral lymphatic glands.

h. Superficial external iliac vein.

i. Superficial epigastric vein.

k. External cutaneous branches of nerves from the lumbar plexus.

[Footnote: Mr. Lawrence (Treatise on Ruptures) remarks, "How often it may be invested by a protrusion of the fascia transversalis, I cannot hitherto determine." Mr. Stanley has presented to St. Bartholomew's Hospital several specimens of this hernia invested by the fascia. Hesselbach speaks of the fascia as being always present. Cloquet mentions it as being present always, except in such cases as where, by being ruptured, the sac protrudes through it. Langenbeck states that the fascia is constantly protruded as a covering to this hernia: "Quia hernia inguinalis interna non in canalis abdominalis aperturam internam transit, tunicam vaginalem communem intrare nequit; parietem autem canalis abdominalis internum aponeuroticum, in quo fovea inguinalis interna, et qui ex adverso annulo abdominali est, ante se per annulum trudit." (Comment, ad illust. Herniarum, &c.) Perhaps the readiest and surest explanation which can be given to these differences of opinion may be had from the following remark:--"Culter enim semper has partes extricat, quae involucro adeo inhaerent, ut pro lubitu musculum (membranam) efformare queas unde magnam illam inter anatomicos discrepantiam ortam conjicio." (Camper. Icones Herniarum.)]

The variety in the number of investments of the internal inguinal hernia (especially as regards the presence or absence of the conjoined tendon and cremaster) appears to me to be dependent, 1st, upon the position whereat this hernia occurs; 2nd, upon the state of the parts through which it passes; and 3rd, upon the manner in which the dissection happens to be conducted.

The precise relations which the internal hernia holds in respect to the epigastric and spermatic vessels are also mainly dependent (as in the external variety) upon the situation where it traverses the groin. The epigastric artery courses outside the neck of its sac, sometimes in close connexion with this part--at other times, at some distance from it, according as the neck may happen to be wide and near the vessel, or narrow, and removed from it nearer to the median line. At the external ring, H, (Plate 34,) the sac of this hernia, g, protrudes on the inner side of the spermatic vessels, f; and the size of the hernia distending the ring, removes these vessels at a considerable interval from, I, the crista pubis. At the ring, H, (Plate 34,) the investments, g f, of the direct hernia are not always distinct from those of the oblique hernia, g f, (Plate 33); for whilst in both varieties the intestine and the spermatic vessels are separated from actual contact by the sac, yet it is true that the direct hernia, as well as the oblique, may occupy the inguinal canal. It is in relation to the epigastric artery alone that the direct hernia differs essentially from the oblique variety; for I find that both may be enclosed in the same structures as invest the spermatic vessels.

The external ring of the male groin is larger than that of the female; and this circumstance, with others of a like nature, may account for the fact, that the female is very rarely the subject of the direct hernia. In the male, the direct hernia is found to occur much less frequently than the oblique, and this we might, a priori, expect, from the anatomical disposition of the parts. But it is true, nevertheless, that the part where the direct hernia occurs is not defended so completely in some male bodies as it is in others. The conjoined tendon, which is described as shielding the external ring, is in some cases very weak, and in others so narrow, as to offer but little support to this part of the groin.

DESCRIPTION OF THE FIGURES OF PLATES 32, 33, & 34.

PLATE 32.

A. That part of the ilium which abuts against the sacrum.

B. The spine of the ischium.

C. The tuberosity of the ischium.

D. The symphysis pubis.

E. Situation of the anterior superior iliac spine.

F. Crest of the ilium.

G. Iliacus muscle.

H. Psoas magnus muscle supporting the spermatic vessels.

I. Transversalis muscle.

K. Termination of the sheath of the rectus muscle.

L1 L2 L3. The iliac, transverse and pelvic portions of the transversalis fascia.

M M. The peritonaeum lining the groin.

N. The epigastric vessels lying between the peritonaeum, M, and the transversalis fascia, L2. O. The umbilical ligament.

P. The neck of the sac of an external inguinal hernia formed before the spermatic vessels.

Q. An interval which occasionally occurs between the umbilical ligament and the epigastric artery.

R and Q. Situations where the direct inguinal hernia occurs when, as in this case, the umbilical ligament crosses the space named the internal fossa--the triangle of Hesselbach.

S. Lower part of the right spermatic cord.

T. The bulb of the urethra.

U. External iliac vein covered by the peritonaeum.

V. External iliac artery covered by the peritonaeum.

W. Internal iliac artery.

X. Common iliac artery.

[Footnote: Cases of this double hernia (external and internal) have been met with by Wilmer, Arnaud, Sandifort, Richter, and others. A plurality of the same variety of hernia may also occur on the same side. A complete and incomplete external inguinal hernia existing in the one groin, is recorded by Mr. Aston Key in his edition of Sir Astley Cooper's work on Hernia. Sir Astley Cooper states his having met with three internal inguinal herniae in each inguinal region. (Ing. et Congenit. Hernire.) ]

Returning, however, to the more frequent conditions of inguinal hernia--viz., those in which either the direct or the oblique variety occurs alone--it should be remembered that a hernia originally oblique, H, Plates 35 and 37, may, when of long standing, and having attained a large size, destroy, by its gravitation, the obliquity of the inguinal canal to such a degree as to bring the internal, H, Plate 35, opposite to the external ring, as at I, and thereby exhibit all the appearance of a hernia originally direct, I, Plate 37. In such a case, the epigastric artery, F, which lies on the outer side of the neck of a truly direct hernia, I, Plate 37, will be found to course on the inner side, G, of the neck of this false-seeming direct hernia, I, Plate 35.

In the trial made for replacing the protruded bowel by the taxis, two circumstances should be remembered in order to facilitate this object: 1st, the abdominal parietes should be relaxed by supporting the trunk forward, and at the same time flexing the thigh on the trunk; 2nd, as every complete hernial protrusion becomes distended more or less beyond the seat of stricture--wherever this may happen to be--its reduction by the taxis should be attempted, with gradual, gentle, equable pressure, so that the sac may be first emptied of its fluid. That part of the hernia which protruded last should be replaced first. The direction in which the hernia protrudes must always determine the direction in which it is to be reduced. If it be the external or oblique variety, the viscus is to be pushed upwards, outwards, and backwards; if it be the internal or direct variety, it is to be reduced by pressure, made upwards and backwards. Pressure made in this latter direction will serve for the reduction of that hernia which, from being originally external and oblique, has assumed the usual position of the internal or direct variety.

The seat of the stricture in an external inguinal hernia is found to be situated either at the internal ring, corresponding to the neck of the sac, or at the external ring. Between these two points, which "bound the canal," and which are to be regarded merely as passive agents in causing stricture of the protruding bowel, the lower parts of the transversalis and internal oblique muscles embrace the herniary sac, and are known at times to be the cause of its active strangulation or spasm.

The seat of stricture in an internal hernia may be either at the neck of its sac, I, Plate 37, or at the external ring, T, Plate 38; and according to the locality where this hernia enters the inguinal wall, the nature of its stricture will vary. If the hernia pass through a cleft in the conjoined tendon, f, Plate 38, this structure will constrict its neck all around. If it pass on the outer margin of this tendon, then the neck of the sac, bending inwards in order to gain the external ring, will be constricted against the sharp resisting edge of the tendon. Again, if the hernia enter the inguinal wall close to the epigastric artery, it will find its way into the inguinal canal, become invested by the structures forming this part, and here it may suffer active constriction from the muscular fibres of the transverse and internal oblique or their cremasteric parts. The external ring may be considered as always causing some degree of pressure on the hernia which passes through it.

In both kinds of inguinal herniae, the neck of the sac is described as being occasionally the seat of stricture, and it certainly is so; but never from a cause originating in itself per se, or independently of adjacent structures. The form of the sac of a hernia is influenced by the parts through which it passes, or which it pushes and elongates before itself. Its neck, H, Plate 37, is narrow at the internal ring of the fascia transversalis, because this ring is itself narrowed; it is again narrowed at the external ring, T, Plate 36, from the same cause. The neck of the sac of a direct hernia, I, Plate 37, being formed in the space of the separated fibres of the conjoined tendon, or the pubic part of the transversalis fascia, while the sac itself passes through the resisting tendinous external ring, is equal to the capacities of these outlets. But if these constricting outlets did not exist, the neck of the sac would be also wanting. When, however, the neck of the sac has existed in the embrace of these constricting parts for a considerable period--when it suffers inflammation and undergoes chronic thickening--then, even though we liberate the stricture of the internal ring or the external, the neck of the sac will be found to maintain its narrow diameter, and to have become itself a real seat of stricture. It is in cases of this latter kind of stricture that experience has demonstrated the necessity of opening the sac (a proceeding otherwise not only needless, but objectionable) and dividing its constricted neck.

The fact that the stricture may be seated in the neck of the sac independent of the internal ring, and also that the duplicature of the contained bowel may be adherent to the neck or other part of the interior, or that firm bands of false membrane may exist so as to constrict the bowel within the sac, are circumstances which require that this should be opened, and the state of its contained parts examined, prior to the replacement of the bowel in the abdomen. If the bowel were adherent to the neck of the sac, we might, when trying to reduce it by the taxis, produce visceral invagination; or while the stricture is in the neck of the sac, if we were to return this and its contents en masse (the "reduction en bloc") into the abdomen, it is obvious that the bowel would be still in a state of strangulation, though free of the internal ring or other opening in the inguinal wall.

The operation for the division of the stricture by the knife is conducted in the following way: an incision is to be made through the integuments, adipous membrane, and superficial fascia, of a length and depth sufficient to expose the tendon of the external oblique muscle for an inch or so above the external ring; and the hernia for the same extent below the ring. The length of the incision will require to be varied according to circumstances, but its direction should be oblique with that of the hernia itself, and also over the centre of its longitudinal axis, so as to avoid injuring the spermatic vessels. If the constriction of the hernia be caused by the external ring, a director is to be inserted beneath this part, and a few of its fibres divided. But when the stricture is produced by either of the muscles which lie beneath the aponeurosis of the external oblique, it will be necessary to divide this part in order to expose and incise them.

When the thickened and indurated neck of the sac is felt to be the cause of the strangulation, or when the bowel cannot be replaced, in consequence of adhesions which it may have contracted with some part of the sac, it then becomes necessary to open this envelope. And now the position of the epigastric artery is to be remembered, so as to avoid wounding it in the incision about to be made through the constricted neck of the sac. The artery being situated on the inner side of the neck of the sac of an oblique hernia, requires the incision to be made outwards from the external side of the neck; whereas in the direct hernia, the artery being on its outer side, the incision should be conducted inwards from the inner side of the neck. But as the external or oblique hernia may by its weight, in process of time, gravitate so far inwards as to assume the position and appearance of a hernia originally direct and internal, and as by this change of place the oblique hernia, becoming direct as to position, does not at the same time become internal in respect to the epigastric artery,--for this vessel, F, Plate 35, has been borne inwards to the place, G, where it still lies, internal to the neck of the sac, and since, moreover, it is very difficult to diagnose a case of this kind with positive certainty, it is therefore recommended to incise the stricture at the neck of the sac in a line carried directly upwards. (Sir Astley Cooper.) It will be seen, however, on referring to Plates 32, 33, 34, 35, 36, 37, & 38, that an incision carried obliquely upwards towards the umbilicus would be much more likely to avoid the epigastric artery through all its varying relations.

DESCRIPTION OF THE FIGURES OF PLATES 35, 36, 37, & 38.

PLATE 35.

A. Anterior superior spine of the ilium; a, indicates the situation of the middle of Poupart's ligament.

B. Symphysis pubis.

C. Rectus abdominis muscle covered by the fascia transversalis.

D. The peritonaeum lining the groin.

E. The situation of the conjoined tendon resisting the further progress of the external hernia gravitating inwards.

F. A dotted line indicating the original situation of the epigastric artery in the external hernia.

G. The new position assumed by the epigastric artery borne inwards by the weight of the old external hernia.

H. The original situation of the neck of the sac of the external hernia.

I. The new situation assumed by the neck of the sac of an old external hernia which has gravitated inwards from its original place at H.

K. The external iliac vein covered by the peritonaeum.

L. The external iliac artery covered by the peritonaeum and crossed by the spermatic vessels.

M. The psoas muscle supporting the spermatic vessels and the genito-crural nerve.

N. The iliacus muscle.

O. The transversalis fascia lining the transverse muscle.

[Footnote: Dr. Carpenter (Principles of Human Physiology) remarks, that "the cause of this descent is not very clear. It can scarcely be due merely, as some have supposed, to the contraction of the gubernaculum, since that does not contain any fibrous structure until after the lowering of the testis has commenced." Dr. Sharpey (Quain's Anatomy, 5th edition) observes, that "the office of the gubernaculum is yet imperfectly understood." The opinions of these two distinguished physiologists will doubtless be regarded as an impartial estimate of the results of the researches prosecuted in reference to these questions by Haller, Camper, Hunter, Arnaud, Lobstein, Meckel, Paletta, Wrisberg, Vicq d'Azyr, Brugnone, Tumiati, Seiler, Girardi, Cooper, Bell, Weber, Carus, Cloquet, Curling, and others. From my own observations, I am led to believe that no such muscular structure as a gubernaculum exists, and therefore that the descent of the testis is the effect of another cause. Leaving these matters, however, to the consideration of the physiologist, it is sufficient for the surgeon to know that the testis in its transition derives certain coverings from the parietes of the groin, and that a communication is thereby established between the scrotal and abdominal cavities. ]

The general lining membrane of the foetal abdomen is composed of two 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.) ]

[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.]

[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.]

[Footnote: Much difference of opinion prevails as to the true relation which the cord (and consequently the oblique hernia) bears to the lower margins of the oblique and transverse muscles, and their cremasteric prolongation. Mr. Guthrie (Inguinal and Femoral Hernia) has shown that the fibres of the transversalis, as well as those of the internal oblique, are penetrated by the cord. Albinus, Haller, Cloquet, Camper, and Scarpa, record opinions from which it may be gathered that this disposition of the parts is (with some exceptions) general. Sir Astley Cooper describes the lower edge of the transversalis as curved all round the internal ring and cord. From my own observations, coupled with these, I am inclined to the belief that, instead of viewing these facts as isolated and meaningless particulars, we should now fuse them into the one idea expressed by the philosophic Carus, and adopted by Cloquet, that the cremaster is a production of the abdominal muscles, formed mechanically by the testicle, which in its descent dilates, penetrates, and elongates their fibres.]

[Footnote: According to Mr. Lawrence and M. Cloquet, most of the serous cysts found around hernial tumours are ancient sacs obliterated at the neck, and adhering to the new swelling (opera cit.)]

[Footnote: As the external hernia, Fig. 4, Plate 42, may displace the epigastric artery inwards, so may the internal hernia, Fig. 1, Plate 42, displace the artery outwards. Mr. Lawrence, Sir Astley Cooper, Scarpa, Hesselbach, and Langenbeck, state, however, that the internal hernia does not disturb the artery from its usual position three-fourths of an inch from the external ring.]

[Footnote 2: The "upper cornu of the saphenous opening," the "falciform process" (Burns), and the "femoral ligament" (Hey), are names applied to the same part. With what difficulty and perplexity does this impenetrable fog of surgical nomenclature beset the progress of the learner!]

[Footnote 3: The neck of the sac at the femoral ring lies very deep, in the undissected state of the parts (Lawrence).]

The crural hernia is much more liable to suffer constriction than the inguinal hernia. The peculiar sinuous course which the former takes from its point of origin, at the crural ring, to its place on Poupart's ligament, and the unyielding fibrous structures which form the canal through which it passes, fully account for the more frequent occurrence of this casualty. The neck of the sac may, indeed, be supposed always to suffer more or less constriction at the crural ring. The part which occupies the canal is also very much compressed; and again, where the hernia turns over the falciform process, this structure likewise must cause considerable compression on the bowel in the sac. [Footnote] This hernia suffers stricture of the passive kind always; for the dense fibrous bands in its neighbourhood compress it rather by withstanding the force of the herniary mass than by reacting upon it. There are no muscular fibres crossing the course of this hernia; neither are the parts which constrict it likely to change their original position, however long it may exist. In the inguinal hernia, the weight of the mass may in process of time widen the canal by gravitating; but the crural hernia, resting on the pubic bone, cannot be supposed to dilate the crural ring, however greatly the protrusion may increase in size and weight.

[Footnote: Sir A. Cooper (Crural Hernia) is of opinion that the stricture is generally in the neck of the sheath. Mr. Lawrence remarks, "My own observations of the subject have led me to refer the cause of stricture to the thin posterior border (Gimbernat's ligament) of the crural arch, at the part where it is connected to the falciform process." (Op. cit.) This statement agrees also with the experience of Hey, (Practical Obs.)]

DESCRIPTION OF THE FIGURES OF PLATES 43 & 44.

PLATE 43.

FIGURE 1.

A. Anterior superior iliac spine.

B. Iliacus muscle, cut.

C. Anterior crural nerve, cut.

D. Psoas muscle, cut.

E. Femoral artery enclosed in e, its compartment of the femoral sheath.

F. Femoral vein in its compartment, f, of the femoral sheath.

G. The fascia propria of the hernia; g, the contained sac.

H. Gimbernat's ligament.

I. Round ligament of the uterus.

The taxis, in a case of crural hernia, should be conducted in accordance with anatomical principles. The fascia lata, Poupart's ligament, and the abdominal aponeurosis, are to be relaxed by bending the thigh inwards to the hypogastrium. By this measure, the falciform process, 6, is also relaxed; but I doubt whether the situation occupied by Gimbernat's ligament allows this part to be influenced by any position of the limb or abdomen. The hernia is then to be drawn from its place above Poupart's ligament, (if it have advanced so far,) and when brought opposite the saphenous opening, gentle pressure made outwards, upwards, and backwards, so as to slip it beneath the margin of the falciform process, will best serve for its reduction. When this cannot be effected by the taxis, and the stricture still remains, the cutting operation is required.

The precise seat of the stricture cannot be known except during the operation. But it is to be presumed that the sac and contained intestine suffer constriction throughout the whole length of the canal. [Footnote] Previously to the commencement of the operation, the urinary bladder should be emptied; for this organ, in its distended state, rises above the level of the pubic bone, and may thus be endangered by the incision through the stricture--especially if Gimbernat's ligament be the structure which causes it.

[Footnote: "The seat of the stricture is not the same in all cases, though, in by far the greater number of instances, the constriction is relieved by the division upwards and inwards of the falciform process of the fascia lata, and the lunated edge of Gimbernat's ligament, where they join with each other. In some instances, it will be the fibres of the deep crescentic (femoral) arch; in others, again, the neck of the sac itself, and produced by a thickening and contraction of the subserous and peritonaeal membranes where they lie within the circumference of the crural ring."--Morton (Surgical Anatomy of the Groin p. 148).]

An incision commencing a little way above Poupart's ligament, is to be carried vertically over the hernia, parallel with, but to the inner side of its median line. This incision divides the skin and subcutaneous adipose membrane, which latter varies considerably in quantity in several individuals. One or two small arteries (superficial pubic, &c.) may be divided, and some lymphatic bodies exposed. On cautiously turning aside the incised adipose membrane contained between the two layers of the superficial fascia, the fascia propria, 9, Figs. 4, 5, Plate 46, of the hernia is exposed. This envelope, besides varying in thickness in two or more cases, may be absent altogether. The fascia closely invests the sac, 12; but sometimes a layer of fatty substance interposes between the two coverings, and resembles the omentum so much, that the operator may be led to doubt whether or not the sac has been already opened. The fascia is to be cautiously slit open on a director; and now the sac comes in view. The hernia having been drawn outwards, so as to separate it from the inner wall of the crural canal, a director [Footnote] is next to be passed along the interval thus left, the groove of the instrument being turned to the pubic side. The position of the director is now between the neck of the sac and the inner wall of the canal. The extent to which the director passes up in the canal will vary according to the suspected level of the stricture. A probe-pointed bistoury is now to be slid along the director, and with its edge turned upwards and inwards, according to the seat of stricture, the following mentioned parts are to be divided--viz., the falciform process, 6; the inner wall of the canal, which is continuous with the fascia propria, 9; Gimbernat's ligament, 8; and the conjoined tendon, 4; where this is inserted with the ligament into the pectineal ridge. By this mode of incision, which seems to be all-sufficient for the liberation of the stricture external to the neck of the sac, we avoid Poupart's ligament; and thereby the spermatic cord, 3, and epigastric artery, 1, are not endangered. The crural canal being thus laid open on its inner side, and the constricting fibrous bands being severed, the sac may now be gently manipulated, so as to restore it and its contents to the cavity of the abdomen; but if any impediment to the reduction still remain, the cause, in all probability, arises either from the neck of the sac having become strongly adherent to the crural ring, or from the bowel being bound by bands of false membrane to the sac. In either case, it will be necessary to open the sac, and examine its contents. The neck of the sac is then to be exposed by an incision carried through the integument across the upper end of the first incision, and parallel with Poupart's ligament. The neck is then to be divided on its inner side, and the exposed intestine may now be restored to the abdomen.

[Footnote: The finger is the safest director; for at the same time that it guides the knife it feels the stricture and protects the bowel. As all the structures which are liable to become the seat of stricture--viz., the falciform process, Gimbernat's ligament, and the conjoined tendon, lie in very close apposition, a very short incision made upwards and inwards is all that is required.]

The main artery of the lower limb may be exposed and tied in any part of its course from the aorta to the popliteal space. But the situation most eligible for performing such an operation depends of course upon circumstances, both anatomical and pathological. If an aneurism affect the popliteal part of the vessel, or if, from whatever cause arising, it be found expedient to tie the femoral above this part, the place best suited for the operation is that where the artery, W, first passes under cover of the sartorius muscle. [Footnote] For, considering that the vessel gives off no important branch destined to supply any part of the thigh or leg between the profundus branch and those into which it divides below the popliteal space, the arrest to circulation will be the same in amount at whichever part of the vessel between these two points the ligature be applied. But since the vessel in the situation specified can be reached with greater facility here than elsewhere lower down; and since, moreover, a ligature applied to it here will be sufficiently removed from the profundus branch above, and the seat of disease below, to produce the desired result, the choice of the operator is determined accordingly. The steps of the operation performed at the situation W, where the artery is about to pass beneath the sartorius, are these: an incision of sufficient length--from two to three inches--is to be made over the course of the vessel, so as to divide the skin and adipose membrane, and expose the fascia lata, through which the inner edge of the sartorius muscle becomes now readily discernible. A vein (anterior saphena) may be found to cross in this situation, but the saphena vein proper is not met with, as this lies nearer the inner side of the thigh. The fascia having been next divided, the edge of the sartorius is to be turned aside, and now the pulsation of the artery in its sheath will indicate its exact position. The sheath is next to be opened, for an extent sufficient only to carry the point of the ligature-needle safely around the artery, care being taken not to injure the femoral vein, which lies close behind it, and also to exclude any nerve which may lie in contact with the vessel.

[Footnote: This is the situation chosen by Scarpa for arresting by ligature the circulation through the femoral artery in cases of popliteal aneurism. The reasons stated in the text are those which determine the surgeon to perform the operation in this place in preference to that (the lower third of the thigh) where Mr. Hunter first proposed to tie the vessel.]

If an aneurism affect the common femoral portion of the artery, the external iliac part would require to be tied, because, between the seat of the tumour and the epigastric and circumflex ilii branches above, there would not be sufficient space to allow the ligature to rest undisturbed; and even if the aneurism arose from the femoral below the profundus branch in the upper third of the thigh, or if, after amputation of the thigh, a secondary haemorrhage took place from the femoral and the profunda arteries, a ligature would with more safety be applied to the external iliac part than to the common femoral; because of this latter, even when of its clear normal length, presenting so small an interval between the epigastric and profundus branches. In addition to this, it must be noticed, that occasionally the profundus itself, or some one of its branches, (external and internal circumflex, &c.), arises as high up as Poupart's ligament, close to the origin of the epigastric and circumflex iliac. [Footnote]

[Footnote: The main artery (Plate 47) has been exposed in the iliac and femoral regions with the object of showing the relation which its parts bear to each other and to the whole; all the other dissections have been made upon the same plan, the practical tendency of which will be illustrated when considering the subject of arterial anastomosis.]

The external iliac part of the artery, G I, when requiring to be tied, may be reached in the following way: an incision, commencing above the anterior iliac spine, B, is to be carried inwards parallel to, and above, Poupart's ligament, D, as far as the outer margin of the internal abdominal ring. This incision is the one best calculated for avoiding the epigastric artery, and for not disturbing the peritonaeum more than is necessary. The skin and the three abdominal muscles having been successively incised, the fibrous transversalis fascia is next to be carefully divided, so as to expose the peritonaeum. This membrane is then to be gently raised by the fingers, from off the iliacus and psoas muscles as far inwards as the margin of the true pelvis where the artery lies. On raising the peritonaeum the spermatic vessels will be found adhering to it. The iliac artery itself is liable to be displaced by adhering to the serous membrane, when this is being detached from the inner side of the psoas muscle. [Footnote] The artery having been divested of its serous covering as far up as a point midway between I G, the epigastric and internal iliac branches, the ligature is to be passed around it in this place, as being equidistant from these two sources of disturbance. As the vein, K, lies close along the inner side of the artery, the point of the instrument should first be inserted between them, and passed from within outwards, in order to avoid wounding the vein. If an aneurism affect the upper end of the external iliac artery, it is proposed to tie the common iliac; but this is an operation of so serious a nature, that it can in this respect be exceeded only by tying the aorta itself. The common iliac artery is so situated, that it can as easily be reached from the groin upwards as from the side of the abdomen inwards, and in both directions the peritonaeum would have to be disturbed to an equal extent.

[Footnote: The student, in operating upon the dead subject, is often puzzled to find that the iliac artery does not appear in its usual situation, unaware at the time that he has lifted the vessel in connexion with the peritonaeum. I have once seen a very distinguished surgeon, whilst performing this operation on the living body, at fault owing to the same cause.]

DESCRIPTION OF PLATE 47.

A. The aorta at its point of bifurcation.

B. The anterior superior iliac spine.

C. The symphysis pubis.

D. Poupart's ligament, immediately above which are seen the circumflex ilii and epigastric arteries, with the vas deferens and spermatic vessels.

E E*. The right and left iliac muscles covered by the peritonaeum; the external cutaneous nerve is seen through the membrane.

F. The vena cava.

G G*. The common iliac arteries giving off the internal iliac branches on the sacro-iliac symphyses; g g, the right and left ureters.

H H*. The right and left common iliac veins.

I I*. The right and left external iliac arteries, each is crossed by the circumflex ilii vein.

K K *. The right and left external iliac veins.

L. The urinary bladder covered by the peritonaeum.

M. The rectum intestinum.

N. The profundus branch of the femoral artery.

O. The femoral vein; 0, the saphena vein.

P. The anterior crural nerve.

Q. The sartorius muscle, cut.

S. The pectinaeus muscle.

T. The adductor longus muscle.

U. The gracilis muscle.

V. The tendinous sheath given off from the long adductor muscle, crossing the vessels, and becoming adherent to the vastus internus muscle.

W. The femoral artery. The letter is on the part where the vessel becomes first covered by the sartorius muscle.

[Footnote: The distance between any two given parts is found to vary in different cases. "In subjects of an advanced age," Mr. Stanley remarks, "a deep perinaeum, as it is termed, is frequently met with. This may be occasioned either by an unusual quantity of fat in the perinaeum, or by an enlarged prostate, or by the dilatation of that part of the rectum which is contiguous to the prostate and bladder. Under either of these circumstances, the prostate and bladder become situated higher in the pelvis than naturally, and consequently at a greater distance from the perinaeum."--On the Lateral Operation of Lithotomy.]

The arteries of the bladder are derived from the branches of the internal iliac, S. The rectum receives its arteries from the inferior mesenteric and pudic. The veins which course upwards from the rectum are large and numerous, and devoid of valves. When these veins become varicose, owing to a stagnation of their circulation, produced from whatever cause, the bowel is liable to be affected with haemorrhoids or to assume a haemorrhagic tendency.

The pudic artery, S s, is a branch of the internal iliac. It passes from the pelvis by the great sciatic foramen, below the pyriformis muscle, and in company with the sciatic artery. The pudic artery and vein wind around the spine, E, of the ischium, where they are joined by the pudic nerve, derived from, T, the sacral plexus. The artery, in company with the nerve and vein, re-enters the pelvis by the small sciatic foramen, and gets under cover of a dense fibrous membrane (obturator fascia), between which and the obturator muscle, it courses obliquely downwards and forwards to the forepart of the perinaeum. At the place where the vessel re-enters the pelvis, it lies removed at an interval of an inch and a half from the perinaeum, but becomes more superficial as it approaches the subpubic space, N. The levator ani muscle separates the pudic vessels and nerves from the sides of the rectum and bladder. The principal branches given off from the pudic artery of either side, are (1st), the inferior hemorrhoidal, to supply the lower end of the rectum; (2nd), the transverse and superficial perinaeal; (3rd), the artery of the bulb; (4th), that which enters the corpus cavernosum of the penis, N; and (5th), the dorsal artery of the penis. [Footnote] The branches given off from the pudic nerve correspond in number and place to those of the artery. Having now considered the relations of the pelvic organs in a lateral view, we are better prepared to understand these relations when seen at their perinaeal aspect.

[Footnote: The pudic artery, or some one of its branches, occasionally undergoes marked deviations from the ordinary course. In Mr. Quain's work, ("Anatomy of the Arteries,") a case is represented in which the artery of the bulb arose from the pudic as far back as the tuber ischii, and crossed the line of incision made in the lateral operation of lithotomy. In another figure is seen a vessel ("accessory pudic"), which, passing between the base of the bladder and the levator ani muscle, crosses in contact with the left lobe of the prostate.]

DESCRIPTION OF PLATES 48 & 49.

PLATE 48.

A. The anterior superior iliac spine.

B. The anterior inferior iliac spine.

C. The acetabulum; c, the ligamentum teres.

D. The tuber ischii.

E. The spine of the ischium.

F. The pubic horizontal ramus.

G. The summit of the bladder covered by the peritonaeum.

H. The femoral artery.

I. The femoral vein.

K. The anterior crural nerve.

L. The thyroid ligament.

M. The spermatic cord.

N. The corpus cavernosum penis; n, its artery.

O. The urethra; o, the bulbus urethrae.

P. The sphincter ani muscle.

Q. The coccyx.

R. The sacro-sciatic ligament.

S. The pudic artery and nerve.

T. The sacral nerves.

U. The pyriformis muscle, cut.

V. The gluteal artery.

W. The small gluteus muscle.

[Footnote: "The object in following this method," Mr. Liston observes, "is to avoid all interference with the reflexion of the ilio-vesical fascia from the sides of the pelvic cavity over the base of the gland and side of the bladder. If this natural boundary betwixt the external and internal cellular tissue is broken up, there is scarcely a possibility of preventing infiltration of the urine, which must almost certainly prove fatal. The prostate and other parts around the neck of the bladder are very elastic and yielding, so that without much solution of their continuity, and without the least laceration, the opening can be so dilated as to admit the fore-finger readily through the same wound; the forceps can be introduced upon this as a guide, and they can also be removed along with a stone of considerable dimensions, say from three to nearly five inches in circumference, in one direction, and from four to six in the largest."--Practical Surgery, page 510. This doctrine (founded, no doubt, on Mr. Liston's own great experience) coincides with that first expressed by Scarpa, Le Cat, and others. Sir Benjamin Brodie, Mr. Stanley, and Mr. Syme are also advocates for limited incisions, extending no farther than a partial division of the prostate, the rest being effected by dilatation. The experience, however, of Cheselden, Martineau, and Mr. S. Cooper, inclined them in favour of a rather free incision of the prostate and neck of the bladder proportioned to the size of the calculus, so that this may be extracted freely, without lacerating or contusing the parts, "and," says the distinguished lithotomist Klein, "upon this basis rests the success of my operations; and hence I invariably make it a rule to let the incision be rather too large than too small, and never to dilate it with any blunt instrument when it happens to be too diminutive, but to enlarge it with a knife, introduced, if necessary, several times."--Practische Ansichten der Bedeutendsten Chirurgische Operationen. Opinions of the highest authority being thus opposed, in reference to the question whether free or limited incisions in the neck of the bladder are followed respectively by the greater number of fatal or favourable results, and these being thought mainly to depend upon whether the pelvic fascia be opened or not, one need not hesitate to conclude, that since facts seem to be noticed in support of both modes of practice equally, the issue of the cases themselves must really be dependent upon other circumstances, such as the state of the constitution, the state of the bladder, and the relative position of the internal and external incisions. "Some individuals (observes Sir B. Brodie) are good subjects for the operation, and recover perhaps without a bad symptom, although the operation may have been very indifferently performed. Others may be truly said to be bad subjects, and die, even though the operation be performed in the most perfect manner. What is it that constitutes the essential difference between these two classes of cases? It is, according to my experience, the presence or absence of organic disease."--Diseases of the Urinary Organs.]

The position in which the staff is held while the membranous urethra and prostate are being divided should be regulated by the operator himself. If he requires the perinaeum to be protruded and the urethra directed towards the place of the incision, he can effect this by depressing the handle of the instrument a little towards the right groin, taking care at the same time that the point is kept beyond the prostate in the interior of the bladder.

DESCRIPTION OF THE FIGURES OF PLATES 52 & 53.

PLATE 52.

FIGURE 1.

A. The urethra.

B. Accelerator urinae muscle.

C. Central perinaeal tendon.

D D. Right and left erector penis muscle.

E E. The transverse muscles.

F. The anus.

G G. The ischiatic tuberosities.

H. The coccyx.

I I. The glutei muscles.

K K. The levator ani muscle.

L. The left artery of the bulb.

[Footnote: Home describes "a natural constriction of the urethra, directly behind the bulb, which is probably formed with a power of contraction to prevent," &c. This is the part which he says is "most liable to the disease of stricture." (Strictures of the Urethra.) Now, if anyone, even among the acute observing microscopists, can discern the structure to which Home alludes, he will certainly prove this anatomist to be a marked exception amongst those who, for the enforcement of any doctrine, can see any thing or phenomenon they wish to see. And, if Hunter were as the mirror from which Home's mind was reflected, then the observation must be imputed to the Great Original. Upon the question, however, as to which is the most frequent seat of stricture, I find that both these anatomists do not agree, Hunter stating that its usual seat is just in front of the bulb, while Home regrets, as it were, to be obliged to differ from "his immortal friend," and avers its seat to be an infinitesimal degree behind the bulb. Sir A. Cooper again, though arguing that the most usual situation of stricture is that mentioned by Hunter, names, as next in order of frequency, strictures of the membranous and prostatic parts of the urethra. Does it not appear strange now, how questions of this import should have occupied so much of the serious attention of our great predecessors, and of those, too, who at the present time form the vanguard of the ranks of science? Upon what circumstance, either anatomical or pathological, can one part of the urethra be more liable to the organic stricture than another?]

Figs. 1 and 2, Plate 59.--In these figures are presented seven forms of organic stricture occurring, in different parts of the urethra. In a, Fig. 1, the mucous membrane is thrown into a sharp circular fold, in the centre of which the canal, appears much contracted; a section of this stricture appears in b, Fig. 2. In b, Fig. 1, the canal is contracted laterally by a prominent fold of the mucous membrane at the opposite side. In c, Fig. 1, an organized band of lymph is stretched across the canal; this stricture is seen in section in c, Fig. 2. In e, Fig. 1, a stellate band of organized lymph, attached by pedicles to three sides of the urethra, divides the canal into three passages. In d, Fig. 1, the canal is seen to be much contracted towards the left side by a crescentic fold of the lining membrane projecting from the right. In f, the canal appears contracted by a circular membrane, perforated in the centre; a section of which is seen at a, Fig. 2. The form of the organic stricture varies therefore according to the three following circumstances:--1st. When lymph becomes effused within the canal upon the surface of the lining mucous membrane, and contracts adhesions across the canal. 2ndly. When lymph is effused external to the lining membrane, and projects this inwards, thereby narrowing the diameter of the canal. 3rdly. When the outer and inner walls of a part of the urethra are involved in the effused organizable matter, and on contracting towards each other, encroach at the same time upon the area of the canal. This latter state presents the form, which is known as the old callous tough stricture, extending in many instances for an inch or more along the canal. In cases where the urethra becomes obstructed by tough bands of substance, c e, which cross the canal directly, the points of flexible catheters, especially if these be of slender shape, are apt to be bent upon the resisting part, and on pressure being continued, the operator may be led to suppose that the instrument traverses the stricture, while it is most probably perforating the wall of the urethra. But in those cases where the diameter of the canal is circularly contracted, the stricture generally presents a conical depression in front, which, receiving the point of the instrument, allows this to enter the central passage unerringly. A stricture formed by a crescentic septum, such as is seen in b d, Fig. 1, offers a more effectual obstacle to the passage of a catheter than the circular septum like a f.

Fig. 6, Plate 60.--The prostatic canal is bent upwards by the enlarged third lobe to such a degree as to form a right angle with the membranous part of the canal. A bougie is seen to perforate the third lobe, and this is the most frequent mode in which, under such circumstances, and with instruments of the usual imperfect form, access may be gained to the bladder for the relief of retention of urine. "The new passage may in every respect be as efficient as one formed by puncture or incision in any other way." (Fergusson.)

[Footnote: This expression of the fact to which I allude will not, I trust, be extended beyond the limits I assign to it. Though I have every reason to believe, that between the prostate of the male and the uterus of the female, the same amount of analogy exists, as between a coccygeal ossicle and the complete vertebral form elsewhere situated in the spinal series, I am as far from regarding the two former to be in all respects structurally or functionally alike, as I am from entertaining the like idea in respect to the two latter. But still I maintain that between a prostate and a uterus, as between a coccygeal bone and a vertebra, the only difference which exists is one of quantity, and that hence arises the functional difference. A prostate is part of a uterus, just as a coccygeal bone is part (the centrum) of a vertebra. That this is the absolute signification of the prostate I firmly believe, and were this the proper place, I could prove it in detail, by the infallible rule of analogical reasoning. John Hunter has observed that the use of the prostate was not sufficiently known to enable us to form a judgment of the bad consequences of its diseased state. When the part becomes morbidly enlarged, it acts as a mechanical impediment to the passage of urine from the bladder, but from this circumstance we cannot reasonably infer, that while of its normal healthy proportions, its special function is to facilitate the egress of the urine, for the female bladder, though wholly devoid of the prostate, performs its own function perfectly. It appears to me, therefore, that the real question should be, not what is the use of the prostate? but has it any proper function? If the former question puzzled even the philosophy of Hunter, it was because the latter question must be answered in the negative. The prostate has no function proper to itself per se. It is a thing distinct from the urinary apparatus, and distinct likewise from the generative organs. It may be hypertrophied or atrophied, or changed in texture, or wholly destroyed by abscess, and yet neither of the functions of these two systems of organs will be impaired, if the part while diseased act not as an obstruction to them. In texture the prostate is similar to an unimpregnated uterus. In form it is, like the uterus, symmetrical. In position it corresponds to the uterus. The prostate has no ducts proper to itself. Those ducts which are said to belong to it (prostatic ducts) are merely mucous cells, similar to those in other parts of the urethral lining membrane. The seminal ducts evidently do not belong to it. The texture of the prostate is not such as appears in glandular bodies generally. In short, the facts which prove what it is not, prove what it actually is--namely, a uterus arrested in its development, and as a sign of that all-encompassing law in nature, which science expresses by the term "unity in variety." This interpretation of the prostate, which I believe to be true to nature, will last perhaps till such time as the microscopists shall discover in its "secretion" some species of mannikins, such as may pair with those which they term spermatozoa.]

Fig. 1, Plate 61.--The prostate, a b, is here represented thinned in its walls above and below. The lower wall is dilated into a pouch caused by the points of misdirected instruments in catheterism having been rashly forced against it.

[Footnote: When a stricture exists immediately behind the bulb, this circumstance will, of course, favour the occurrence of the accident. "False passages (observes Mr. Benjamin Phillips) are less frequent here (in the membranous part of the urethra) than in the bulbous portion of the canal. The reason of this must be immediately evident: false passages are ordinarily made in consequence of the difficulty experienced in the endeavour to pass an instrument through the strictured portion of the tube. Stricture is most frequently seated at the point of junction between the bulbous and membranous portions of the canal; consequently, the false passage will be usually anterior to this latter point."--(On the Urethra, its Diseases. &c., p. 15.) ]

[Footnote: Both lobes of the prostate are equally liable to chronic enlargement. Home believed the left lobe to be oftener increased in size than the right. Wilson (on the Male Urinary and Genital Organs) mentions several instances of the enlargement of the right lobe. No reason can be assigned why one lobe should be more prone to hypertrophy than the other, even supposing it to be matter of fact, which it is not. But the observations made by Cruveilhier (Anat. Pathol.), that the lobulated projections of the prostate always take place internally at its vesical aspect, is as true as the manner in which he accounts for the fact is plausible. The dense fibrous envelope of the prostate is sufficient to repress its irregular growth externally.]

Fig. 11, Plate 61.--Both lobes of the prostate are enlarged, and from the base of each a mass projects prominently around the vesical orifice, a b. The prostatic urethra has been moulded to the shape of the instrument, which was retained in it for a considerable time.

FIG. 1, Plate 63.--The lateral lobes of the prostate, 3, 4, are enlarged, and contract the prostatic canal. Behind them the third lobe of smaller size occupies the vesical orifice, and completes the obstruction. The walls of the bladder have hence become fasciculated and sacculated. One sac, 1, projects from the summit of the bladder; another, 2, containing a stone, projects laterally. When a stone occupies a sac, it does not give rise to the usual symptoms as indicating its presence, nor can it be always detected by the sound.

[Footnote 2: For an analysis of the occasional peculiarities of these primary veins in the human subject, see an able and original monograph in the Philosophical Transactions, Part 1., 1850, entitled, "On the Development of the Great Anterior Veins in Man and Mammalia." By John Marshall, F.R.C.S., &c. ]

IX.--The portal system of veins passing to the liver, and the hepatic veins passing from this organ to join the inferior vena cava, exhibit in respect to the median line of the body an example of a-symmetry, since appearing on the right side, they have no counterparts on the left. As the law of symmetry seems to prevail universally in the development of organized beings, forasmuch as every lateral organ or part has its counterpart, while every central organ is double or complete, in having two similar sides, then the portal system, as being an exception to this law, is as a natural note of interrogation questioning the signification of that fact, and in the following observations, it appears to me, the answer may be found. Every artery in the body has its companion vein or veins. The inferior vena cava passes sidelong with the aorta in the abdomen. Every branch of the aorta which ramifies upon the abdominal parietes has its accompanying vein returning either to the vena cava or the vena azygos, and entering either of these vessels at a point on the same level as that at which itself arises. The renal vessels also have this arrangement. But all the other veins of the abdominal viscera, instead of entering the vena cava opposite their corresponding arteries, unite into a single trunk (vena portae), which enters the liver. The special purpose of this destination of the portal system is obvious, but the function of a part gives no explanation of its form or relative position, whether singular or otherwise. On viewing the vessels in presence of the general law of symmetrical development, it occurs to me that the portal and hepatic veins form one continuous system, which taken in the totality, represents the companion veins of the arteries of the abdominal viscera. The liver under this interpretation appears as a gland developed midway upon these veins, and dismembering them into a mesh of countless capillary vessels, (a condition necessary for all processes of secretion,) for the special purpose of decarbonizing the blood. In this great function the liver is an organ correlative or compensative to the lungs, whose office is similar. The secretion of the liver (bile) is fluidform; that of the lungs is aeriform. The bile being necessary to the digestive process, the liver has a duct to convey that product of its secretion to the intestines. The trachea is as it were the duct of the lungs. In the liver, then, the portal and hepatic veins being continuous as veins, the two systems, notwithstanding their apparent distinctness, caused by the intervention of the hepatic lobules, may be regarded as the veins corresponding with the arteries of the coeliac axis, and the two mesenteric. The hepatic artery and the hepatic veins evidently do not pair in the sense of afferent and efferent, with respect to the liver, both these vessels having destinations as different as those of the bronchial artery and the pulmonary veins in the lungs. The bronchial artery is attended by its vein proper, while the vein which corresponds to the hepatic artery joins either the hepatic or portal veins traversing the liver, and in this position escapes notice.[Footnote]

[Footnote: In instancing these facts, as serving under comparison to explain how the hepatic vessels constitute no radical exception to the law of symmetry which presides over the development and distribution of the vascular system as a whole, I am led to inquire in what respect (if in any) the liver as an organ forms an exception to this general law either in shape, in function, or in relative position. While seeing that every central organ is single and symmetrical by the union of two absolutely similar sides, and that each lateral pair of organs is double by the disunion of sides so similar to each other in all respects that the description of either side serves for the other opposite, it has long since seemed to me a reasonable inference that, since the liver on the right has no counterpart as a liver on the left, and that, since the spleen on the left has no counterpart as a spleen on the right, so these two organs (the liver and spleen) must themselves correspond to each other, and as such, express their respective significations. Under the belief that every exception (even though it be normal) to a general law or rule, is, like the anomaly itself, alone explicable according to such law, and expressing a fact not more singular or isolated from other parallel facts than is one form from another, or from all others constituting the graduated scale of being, I would, according to the light of this evidence alone, have no hesitation in stating that the liver and spleen, as opposites, represent corresponding organs, even though they appeared at first view more dissimilar than they really are. In support of this analogy of both organs, which is here, so far as I am aware, originally enunciated for anatomical science, I record the following observations:--1st. Between the opposite parts of the same organic entity (between the opposite leaves of the same plant, for example), nature manifests no such absolute difference in any case as exists between the leaf of a plant and of a book. 2ndly. When between two opposite parts of the same organic form there appears any differential character, this is simply the result of a modification or metamorphosis of one of the two perfectly similar originals or archetypes, but never carried out to such an extreme degree as to annihilate all trace of their analogy. 3rdly. The liver and the spleen are opposite parts; and as such, they are associated by arteries which arise by a single trunk (coeliac axis) from the aorta, and branch right and left, like indices pointing to the relationship between both these organs, in the same manner as the two emulgent arteries point to the opposite renal organs. 4thly. The liver is divided into two lobes, right and left; the left is less than the right; that quantity which is wanting to the left lobe is equal to the quantity of a spleen; and if in idea we add the spleen to the left lobe of the liver, both lobes of this organ become quantitatively equal, and the whole liver symmetrical; hence, as the liver plus the spleen represents the whole structural quantity, so the liver minus the spleen signifies that the two organs now dissevered still relate to each other as parts of the same whole. 5thly. The liver, as being three-fourths of the whole, possesses the duct which emanates at the centre of all glandular bodies. The spleen, as being one-fourth of the whole, is devoid of the duct. The liver having the duct, is functional as a gland, while the spleen having no duct, cannot serve any such function. If, in thus indicating the function which the spleen does not possess, there appears no proof positive of the function which it does, perhaps the truth is, that as being the ductless portion of the whole original hepatic quantity, it exists as a thing degenerate and functionless, for it seems that the animal economy suffers no loss of function when deprived of it. 6thly. In early foetal life, the left lobe of the liver touches the spleen on the left side; but in the process of abdominal development, the two organs become separated from each other right and left. 7thly. In animals devoid of the spleen, the liver appears of a symmetrical shape, both its lobes being equal; for that quantity which in other animals has become splenic, is in the former still hepatic. 8thly. In cases of transposition of both organs, it is the right lobe of the liver--that nearest the spleen, now on the right side--which is the smaller of the two lobes, proving that whichever lobe be in this condition, the spleen, as being opposite to it, represents the minus hepatic quantity. From these, among other facts, I infer that the spleen is the representative of the liver on the left side, and that as such, its signification being manifest, there exists no exception to the law of animal symmetry. "Tam miram uniformitatem in planetarum systemate, necessario fatendum est intelligentia et concilio fuisse effectam. Idemque dici possit de uniformitate illa quae est in corporibus animalium. Habent videlicet animalia pleraque omnia, bina latera, dextrum et sinistrum, forma consimili: et in lateribus illis, a posteriore quidem corporis sui parte, pedes binos; ab anteriori autem parte, binos armos, vel pedes, vel alas, humeris affixos: interque humeros collum, in spinam excurrens, cui affixum est caput; in eoque capite binas aures, binos oculos, nasum, os et linguam; similiter posita omnia, in omnibus fere animalibus." --Newton, Optices, sive de reflex, &c. p. 411.]

X.--The heart, though being itself the recipient, the prime mover, and the dispenser of the blood, does not depend either for its growth, vitality, or stimulus to action, upon the blood under these uses, but upon the blood circulating through vessels which are derived from its main systemic artery, and disposed in capillary ramifications through its substance, in the manner of the nutrient vessels of all other organs. The two coronary arteries of the heart arise from the systemic aorta immediately outside the semilunar valves, situated in the root of this vessel, and in passing right and left along the auriculo-ventricular furrows, they send off some branches for the supply of the organ itself, and others by which both vessels anastomose freely around its base and apex. The vasa cordis form an anastomotic circulation altogether isolated from the vessels of the other thoracic organs, and also from those distributed to the thoracic parietes. The coronary arteries are accompanied by veins which open by distinct orifices (foramina Thebesii) into the right auricle. Like the heart itself, its main vessels do not depend for their support upon the blood conveyed by them, but upon that circulated by the small arteries (vasa vasorum) derived either from the vessel upon which they are distributed, or from some others in the neighbourhood. These little arteries are attended by veins of a corresponding size (venules) which enter the venae comites, thus carrying out the general order of vascular distribution to the minutest particular. Besides the larger nerves which accompany the main vessels, there are delicate filaments of the cerebro-spinal and sympathetic system distributed to their coats, for the purpose, as it is supposed, of governing their "contractile movements." The vasa vasorum form an anastomosis as well upon the inner surface of the sheath as upon the artery contained in this part; and hence in the operation for tying the vessel, the rule should be to disturb its connexions as little as possible, otherwise its vitality, which depends upon these minute branches, will, by their rupture, be destroyed in the situation of the ligature, where it is most needed.

XI.--The branches of the systemic aorta form frequent anastomoses with each other in all parts of the body. This anastomosis occurs chiefly amongst the branches of the main arteries proper to either side. Those branches of the opposite vessels which join at the median line are generally of very small size. There are but few instances in which a large blood vessel crosses the central line from its own side to the other. Anastomosis at the median line between opposite vessels happens either by a fusion of their sides lying parallel, as for example (and the only one) that of the two vertebral arteries on the basilar process of the occipital bone; or else by a direct end-to-end union, of which the lateral pair of cerebral arteries, forming the circle of Willis, and the two labial arteries, forming the coronary, are examples. The branches of the main arteries of one side form numerous anastomoses in the muscles and in the cellular and adipose tissue generally. Other special branches derived from the parent vessel above and below the several joints ramify and anastomose so very freely over the surfaces of these parts, and seem to pass in reference to them out of their direct course, that to effect this mode of distribution appears to be no less immediate a design than to support the structures of which the joints are composed.

XII.--The innominate artery. When this vessel is tied, the free direct circulation through the principal arteries of the right arm, and the right side of the neck, head, and brain, becomes arrested; and the degree of strength of the recurrent circulation depends solely upon the amount of anastomosing points between the following arteries of the opposite sides. The small terminal branches of the two occipital, the two auricular, the two superficial temporal, and the two frontal, inosculate with each other upon the sides, and over the vertex of the head; the two vertebral, and the branches of the internal carotid, at the base and over the surface of the brain; the two facial with each other, and with the frontal above and mental below, at the median line of the face; the two internal maxillary by their palatine, pharyngeal, meningeal, and various other branches upon the surface of the parts to which they are distributed; and lastly, the two superior thyroid arteries inosculate around the larynx and in the thyroid body. By these anastomoses, it will be seen that the circulation is restored to the branches of the common carotid almost solely. In regard to the subclavian artery, the circulation would be carried on through the anastomosing branches of the two inferior thyroid in the thyroid body; of the two vertebral, in the cranium and upon the cervical vertebrae; of the two internal mammary, with each other behind the sternum, and with the thoracic branches of the axillary and the superior intercostal laterally; lastly, through the anastomosis of the ascending cervical with the descending branch of the occipital, and with the small lateral offsets of the vertebral.

XIII.--The common carotid arteries, Of these two vessels, the left one arising, in general, from the arch of the aorta, is longer than the right one by the measure of the innominate artery from which the right arises. When either of the common carotids is tied, the circulation will be maintained through the anastomosing branches of the opposite vessels as above specified. When the vertebral or the inferior thyroid branch arises from the middle of the common carotid, this vessel will have an additional source of supply if the ligature be applied to it below the origin of such branch. In the absence of the innominate artery, the right as well as the left carotid will be found to spring directly from the aortic arch.

XIV.--The subclavian arteries. When a ligature is applied to the inner third of this vessel within its primary branches, the collateral circulation is carried on by the anastomoses of the arteries above mentioned; but if the vertebral or the inferior thyroid arises either from the aorta or the common carotid, the sources of arterial supply in respect to the arm will, of course, be less numerous. When the outer portion of the subclavian is tied between the scalenus and the clavicle, while the branches arise from its inner part in their usual position and number, the collateral circulation in reference to the arm is maintained by the following anastomosing branches:--viz., those of the superficialis colli, and the supra and posterior scapular, with those of the acromial thoracic; the subscapular, and the anterior and posterior circumflex around the shoulder-joint, and over the dorsal surface of the scapula; and those of the internal mammary and superior intercostal, with those of the thoracic arteries arising from the axillary. Whatever be the variety as to their mode or place of origin, the branches emanating from the subclavian artery are constant as to their destination. The length of the inner portion of the right subclavian will vary according to the place at which it arises, whether from the innominate artery, from the ascending, or from the descending part of the aortic arch.

XV.--The axillary artery. As this vessel gives off throughout its whole length, numerous branches which inosculate principally with the scapular, mammary, and superior intercostal branches of the subclavian, it will be evident that, in tying it above its own branches, the anastomotic circulation will with much greater freedom be maintained in respect to the arm, than if the ligature be applied below those branches. Hence, therefore, when the axillary artery is affected with aneurism, thereby rendering it unsafe to apply a ligature to this vessel, it becomes not only pathologically, but anatomically, the more prudent measure to tie the subclavian immediately above the clavicle.

XVI.--The brachial artery, When this artery is tied immediately below the axilla, the collateral circulation will be weakly maintained, in consequence of the small number of anastomosing branches arising from it above and below the seat of the ligature. The two circumflex humeri alone send down branches to inosculate with the small muscular offsets from the middle of the brachial artery. When tied in the middle of the arm between the origins of the superior and inferior profunda arteries, the collateral circulation will depend chiefly upon the anastomosis of the former vessel with the recurrent branch of the radial, and of muscular branches with each other. When the ligature is applied to the lower third of the vessel, the collateral circulation will be comparatively free through the anastomoses of the two profundi and anastomotic branches with the radial, interosseous, and ulnar recurrent branches. If the artery happen to divide in the upper part of the arm into either of the branches of the forearm, or into all three, a ligature applied to any one of them will, of course, be insufficient to arrest the direct circulation through the forearm, if this be the object in view.

XVII.--The radial artery. If this vessel be tied in any part of its course, the collateral circulation will depend principally upon the free communications between it and the ulnar, through the medium of the superficial and deep palmar arches and those of the branches derived from both vessels, and from the two interossei distributed to the fingers and back of the hand.

XVIII.--The ulnar artery. When this vessel is tied, the collateral circulation will depend upon the anastomosis of the palmar arches, as in the case last mentioned. While the radial, ulnar, and interosseous arteries spring from the same main vessel, and are continuous with each other in the hand, they represent the condition of a circle of which, when either side is tied, the blood will pass in a current of almost equal strength towards the seat of the ligature from above and below--a circumstance which renders it necessary to tie both ends of the vessel in cases of wounds.

XIX.--The common iliac artery. When a ligature is applied to the middle of this artery, the direct circulation becomes arrested in the lower limb and side of the pelvis corresponding to the vessel operated on. The collateral circulation will then be carried on by the anastomosis of the following branches--viz., those of the lumbar, the internal mammary, and the epigastric arteries of that side with each other, and with their fellows in the anterior abdominal parietes; those of the middle and lateral sacral; those of the superior with the middle and inferior haemorrhoidal; those of the aortic and internal iliac uterine branches in the female; and of the aortic and external iliac spermatic branches in the male. The anastomoses of these arteries with their opposite fellows along the median line, are much less frequent than those of the arteries of the neck and head.

XX.--The external iliac artery. This vessel, when tied at its middle, will have its collateral circulation carried on by the anastomoses of the internal mammary with the epigastric; by those of the ilio-lumbar with the circumflex ilii; those of the internal circumflex femoris, and superior perforating arteries of the profunda femoris, with the obturator, when this branch arises from the internal iliac; those of the gluteal with the external circumflex; those of the latter with the sciatic; and those of both obturators, with each other, when arising--the one from the internal, the other from the external iliac. Not unfrequently either the epigastric, obturator, ilio-lumbar, or circumflex ilii, arises from the middle of the external iliac, in which case the ligature should be placed above such branch.

XXI.--The common femoral artery. On considering the circles of inosculation formed around the innominate bone between the branches derived from the iliac arteries near the sacro-iliac junction, and those emanating from the common femoral, above and below Poupart's ligament, it will at once appear that, in respect to the lower limb, the collateral circulation will occur more freely if the ligature be applied to the main vessel (external iliac) than if to the common femoral below its branches.

XXII.--The superficial femoral artery. When a ligature is applied to this vessel at the situation where it is overlapped by the sartorius muscle, the collateral circulation will be maintained by the following arteries:--the long descending branches of the external circumflex beneath the rectus muscle, inosculate with the muscular branches of the anastomotica magna springing from the lower third of the main vessel; the three perforating branches of the profunda inosculate with the latter vessel, with the sciatic, and with the articular and muscular branches around the knee-joint.

XXIII.--The popliteal artery. When any circumstance renders it necessary to tie this vessel in preference to the femoral, the ligature should be placed above its upper pair of articular branches; for by so doing a freer collateral circulation will take place in reference to the leg. The ligature in this situation will lie between the anastomotic and articular arteries, which freely communicate with each other.

XXIV.--The anterior and posterior tibial and peronoeal arteries. As these vessels correspond to the arteries of the forearm, the observations which apply to the one set apply also to the other. [Footnote]

[Footnote: For a complete history of the general vascular system, see The Anatomy of the Arteries of the Human Body, by Richard Quain, F.R.S., &c., in which work, besides the results of the author's own great experience and original observations, will be found those of Haller's, Scarpa's, Tiedemann's, &c., systematically arranged with a view to operative surgery.]

THE END.