Plate 59.—Figure 1, Figure 2.

Fig. 3, Plate 59.—In this there are seen three separate strictures, a, b, c, situated in the urethra, anterior to the bulb. In some cases there are many more strictures (even to the number of six or seven) situated in various parts of the urethra; and it is observed that when one stricture exists, other slight tightnesses in different parts of the canal frequently attend it. (Hunter.) When several strictures occur in various parts of the urethra, they may occasion as much difficulty in passing an instrument as if the whole canal between the extreme constrictions were uniformly narrowed.



Plate 59.—Figure 3.

Fig. 4, Plate 59.—In this the canal is constricted at the point a, midway between the bulb and glans. A false passage has been made under the urethra by an instrument which passed out of the canal at the point f, anterior to the stricture a, and re-entered the canal at the point c, anterior to the bulb. When a false passage of this kind happens to be made, it will become a permanent outlet for the urine, so long as the stricture remains. For it can be of no avail that we avoid re-opening the anterior perforation by the catheter, so long as the urine prevented from flowing by the natural canal enters the posterior perforation. Measures should be at once taken to remove the stricture.



Plate 59.—Figure 4.

Fig. 5, Plate 59.—The stricture a appears midway between the bulb and glans, the area of the passage through the stricture being sufficient only to admit a bristle to pass. It would seem almost impossible to pass a catheter through a stricture so close as this, unless by a laceration of the part, combined with dilatation.



Plate 59.—Figure 5.

Fig. 6, Plate 59.—Two instruments, a, b, have made false passages beneath the mucous membrane, in a case where no stricture at all existed. The resistance which the instruments encountered in passing out of the canal having been mistaken, no doubt, for that of passing through a close stricture.



Plate 59.—Figure 6.

Fig. 7, Plate 59.—A bougie, b b, is seen to perforate the urethra anterior to the stricture c, situated an inch behind the glans, and after traversing the substance of the right corpus cavernosum d, for its whole length, re-enters the neck of the bladder through the body of the prostate.



Plate 59.—Figure 7.

Fig. 8, Plate 59.—A bougie, c c, appears tearing and passing beneath the lining membrane, d d, of the prostatic urethra. It is remarked that the origin of a false passage is in general anterior to the stricture. It may, however, occur at any part of the canal in which no stricture exists, if the hand that impels the instrument be not guided by a true knowledge of the form of the urethra; and perhaps the accident happening from this cause is the more general rule of the two.



Plate 59.—Figure 8.

Fig. 9, Plate 59.—Two strictures are represented here, the one, e, close to the bulb d, the other, f, an inch anterior to this part. In the prostate, a b, are seen irregularly shaped abscess pits, communicating with each other, and projecting upwards the floor of this body to such a degree, that the prostatic canal appears nearly obliterated.



Plate 59.—Figure 9.

Fig. 10, Plate 59.—Two bougies, d e, are seen to enter the upper wall of the urethra, c, anterior to the prostate, a b. This accident happens when the handle of a rigid instrument is depressed too soon, with the object of raising its point over the enlarged third lobe of the prostate.



Plate 59.—Figure 10.

Fig. 11, Plate 59.—Two instruments appear transfixing the prostate, of which body the three lobes, a, b, c, are much enlarged. The instrument d perforates the third lobe, a; while the instrument e penetrates the right lobe, c, and the third lobe, a. This accident occurs when instruments not possessing the proper prostatic bend are forcibly pushed forwards against the resistance at the neck of the bladder.



Plate 59.—Figure 11.

Fig. 12, Plate 59.—In this case an instrument, d d, after passing beneath part of the lining membrane, e e, anterior to the bulb, penetrates b, the right lobe of the prostate. A second instrument, c c, penetrates the left lobe. A third smaller instrument, f f, is seen to pass out of the urethra anterior to the prostate, and after transfixing the right vesicula seminalis external to the neck of the bladder, enters this viscus at a point behind the prostate. The resistance which the two larger instruments met with in penetrating the prostate, made it seem, perhaps, that a tight stricture existed in this situation, to match which the smaller instrument, f f, was afterwards passed in the course marked out.



Plate 59.—Figure 12.

Figs. 1 to 5, Plate 60, represent a series of prostates, in which the third lobe gradually increases in size. In Fig. 1, which shows the healthy state of the neck of the bladder, unmarked by the prominent lines which are said to bound the space named "trigone vesical," or by those which indicate the position of the "muscles of the ureters," the third lobe does not exist. In Fig. 2 it appears as the uvula vesicae, a. In Fig. 3 the part a is increased, and under the name now of third lobe is seen to contract and bend upwards the prostatic canal. In Fig. 4 the effect which the growth of the lobe, a, produces upon the form of the neck of the bladder becomes more marked, and the part presenting perforations, e e, produced by instruments, indicates that by its shape it became an obstacle to the egress of the urine as well as to the entrance of instruments. A calculus of irregular form is seen to lodge behind the third lobe, and to be out of the reach of the point of a sound, supposing this to enter the bladder over the apex of the lobe. In Fig. 5 the three lobes are enlarged, but the third is most so, and while standing on a narrow pedicle attached to the floor of the prostate, completely blocks up the neck of the bladder. [Footnote]



Plate 60.—Figures 1, 2, 3, 4, 5

[Footnote: On comparing this series of figures, it must appear that the third lobe of the prostate is the product of diseased action, in so far at least as an unnatural hypertrophy of a part may be so designated. It is not proper to the bladder in the healthy state of this organ, and where it does manifest itself by increase it performs no healthy function in the economy. When Home, therefore, described this part as a new fact in anatomy, he had in reality as little reason for so doing as he would have had in naming any other tumour, a thing unknown to normal anatomy. Langenbeck (Neue Bibl. b. i. p. 360) denies its existence in the healthy state. Cruveilhier (Anat. Pathog. liv. xxvii.) deems it incorrect to reckon a third lobe as proper to the healthy bladder.]

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.)



Plate 60.—Figure 6

Fig. 7, Plate 60.—The three lobes of the prostate, a, b, c, are equally enlarged. The prostatic canal is consequently much contracted and distorted, so that an instrument on being passed into the bladder has made a false passage through the third lobe. When a catheter is suspected to have entered the bladder by perforating the prostate, the instrument should be retained in the newly made passage till such time as this has assumed the cylindrical form of the instrument. If this be done, the new passage will be the more likely to become permanent. It is ascertained that all false passages and fistulae by which the urine escapes, become after a time lined with a membrane similar to that of the urethra. (Stafford.)



Plate 60.—Figure 7

Fig. 8, Plate 60.—The three lobes, a, b, c, of the prostate are irregularly enlarged. The third lobe, a a, projecting from below, distorts the prostatic canal upwards and to the right side.



Plate 60.—Figure 8.

Fig. 9, Plate 60.—The right lobe, a c c, of the prostate appears hollowed out so as to form the sac of an abscess which, by its projection behind, pressed upon the forepart of the rectum, and by its projection in front, contracted the area of the prostatic canal, and thereby caused an obstruction in this part. Not unfrequently when a catheter is passed along the urethra, for the relief of a retention of urine caused by the swell of an abscess in this situation, the sac becomes penetrated by the instrument, and, instead of urine, pus flows. The sac of a prostatic abscess frequently opens of its own accord into the neighbouring part of the urethra, and when this occurs it becomes necessary to retain a catheter in the neck of the bladder, so as to prevent the urine entering the sac.



Plate 60.—Figure 9.

Fig. 10, Plate 60.—The prostate presents four lobes of equal size, and all projecting largely around the neck of the bladder. The prostatic canal is almost completely obstructed, and an instrument has made a false passage through the lobe a.



Plate 60.—Figure 10.

Fig. 11, Plate 60.—The third lobe of the prostate is viewed in section, and shows the track of the false passage made by the catheter, d, through it, from its apex to its base. The proper canal is bent upwards from its usual position, which is that at present marked by the instrument in the false passage.



Plate 60.—Figure 11.

Fig. 12, Plate 60.—The prostatic lobes are uniformly enlarged, and cause the corresponding part of the urethra to be uniformly contracted, so as closely to embrace the catheter, d d, occupying it, and to offer considerable resistance to the passage of the instrument.



Plate 60.—Figure 12.

Fig. 13, Plate 60.—The prostate, bc, is considerably enlarged anteriorly, b, in consequence of which the prostatic canal appears more horizontal even than natural. The catheter, d, occupying the canal lies nearly straight. The lower wall, c, of the prostate is much diminished in thickness. A nipple-shaped process, a, is seen to be attached by a pedicle to the back of the upper part, b, of the prostate, and to act like a stopper to the neck of the bladder. The body a being moveable, it will be perceived how, while the bladder is distended with urine, the pressure from above may block up the neck of the organ with this part, and thus cause complete retention, which, on the introduction of a catheter, becomes readily relieved by the instrument pushing the obstructing body aside.



Plate 60.—Figure 13.



COMMENTARY ON PLATES 61 & 62.

DEFORMITIES OF THE PROSTATE.—DISTORTIONS AND OBSTRUCTIONS OF THE PROSTATIC URETHRA.

The prostate is liable to such frequent and varied deformities, the consequence of diseased action, whilst, at the same time, its healthy function (if it have any) in the male body is unknown, that it admits at least of one interpretation which may, according to fact, be given of it—namely, that of playing a principal part in effecting some of the most distressing of "the thousand natural ills that flesh is heir to." But heedless of such a singular explanation of a final cause, the practical surgeon will readily confess the fitting application of the interpretation, such as it is, and rest contented with the proximate facts and proofs. As physiologists, however, it behooves us to look further into nature, and search for the ultimate fact in her prime moving law. The prostate is peculiar to the male body, the uterus to the female. With the exception of these two organs there is not another which appears in the one sex but has its analogue in the opposite sex; and thus these two organs, the prostate and the uterus, appear by exclusion of the rest to approach the test of comparison, by which their analogy becomes as fully manifested as that between the two quantities, a-b, and a+b the only difference which exists depends upon the subtraction or the addition of the quantity, b. The difference between a prostate and a uterus is simply one of quantity, such as we see existing between the male and the female breast. The prostate is to the uterus absolutely what a rudimentary organ is to its fully developed analogue. The one, as being superfluous, is in accordance with nature's law of nihil supervacaneum nihil frutra, arrested in its development, and in such a character appears the prostate. This body is not a gland any more than is the uterus, but both organs being quantitatively, and hence functionally different, I here once more venture to call down an interpretation of the part from the unfrequented bourne of comparative anatomy, and turning it to lend an interest to the accompanying figures even with a surgical bearing, I remark that the prostatic or rudimentary uterus, like a germ not wholly blighted, is prone to an occasional sprouting or increase beyond its prescribed dimensions—a hypertrophy in barren imitation, as it were, of gestation. [Footnote]

[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.



Plate 61.—Figure 1.

Fig. 2, Plate 61.—The prostate, a b, is here seen to be somewhat more enlarged than is natural. A tubercle, b, surmounts the lower part, c, of the prostate, and blocks up the vesical orifice. Catheters introduced by the urethra for retention of urine which existed in this case, have had their points arrested at the bulb, and on being pushed forwards in this direction, have dilated the bulb into the form of a pouch, seen at d. The sinus of the bulb, being the lowest part of the urethral canal, is very liable to be distorted or perforated by the points of instruments descending upon it from above and before. [Footnote]

[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.) ]



Plate 61.—Figure 2

Fig. 3, Plate 61.—A cyst, c, is seen to grow from the left side of the base of the prostate, a b, and to form an obstruction at the vesical orifice.



Plate 61.—Figure 3.

Fig. 4, Plate 61.—A globular excrescence, a, appears blocking up the vesical orifice, and giving to this the appearance of a crescentic slit, corresponding to the shape of the obstructing body. The prostate, b b, is enlarged in both its lateral lobes. A small bougie, c, is placed in the prostatic canal and vesical opening.



Plate 61.—Figure 4

Fig. 5, Plate 61.—The prostate, d, is considerably enlarged, and the vesical orifice is girt by a prominent ring, b b, from the right border of which the nipple-shaped body, a, projects and occupies the outlet. Owing to the retention of urine caused by this state of the prostate, the ureters, c c, have become very much dilated.



Plate 61.—Figure 5.

Fig. 6, Plate 61.—The lateral lobes of the prostate, c c, are seen enlarged, and from the inner side and base of each, irregularly shaped masses, a, b, d, project, and bend the prostatic urethra first to the right side, then to the left. The part, a, resting upon the part, b, acts like a valve against the vesical outlet, which would become closed the tighter according to the degree of superincumbent pressure. A flexible catheter would, in such a case as this, be more likely, perhaps, to follow the sinuous course of the prostatic passage than a rigid instrument of metal.



Plate 61.—Figure 6.

Fig. 7, Plate 61.—A globular mass, a, of large size, occupies the neck of the bladder, and gives the vesical orifice, c, a crescentic shape, convex towards the right side. The two lobes of the prostate, b, are much enlarged.



Plate 61.—Figure 7.

Fig. 8, Plate 61.—The lateral lobes, b b, of the prostate are irregularly enlarged, and the urinary passage is bent towards the right side, c, from the membranous portion, which is central. Surmounting the vesical orifice, c, is seen the tuberculated mass, a, which being moveable, can be forced against the vesical orifice and thus produce complete retention of urine. In this case, also, a flexible catheter would be more suitable than a metallic one.



Plate 61.—Figure 8.

Fig. 9, Plate 61.—The lateral lobes, b b, of the prostate are enlarged. The third lobe, a, projects at the neck of the bladder, distorting the vesical outlet. A small calculus occupies the prostatic urethra, and being closely impacted in this part of the canal, would arrest the progress of a catheter, and probably lead to the supposition that the instrument grated against a stone in the interior of the bladder, in which case it would be inferred that since the urine did not flow through the catheter no retention existed.



Plate 61.—Figure 9, 10.

Fig. 10, Plate 61.—Both lateral lobes, b c, of the prostate appear much increased in size. A large irregular shaped mass, a, grows from the base of the right lobe, and distorts the prostatic canal and vesical orifice. When the lobes of the prostate increase in size in this direction, the prostatic canal becomes much more elongated than natural, and hence the instrument which is to be passed for relieving the existing retention of urine should have a wide and long curve to correspond with the form of this part of the urethra. [Footnote]

[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.



Plate 61.—Figure 11.

Fig. 12, Plate 61.—The prostate, c b, is enlarged and dilated, like a sac. Across the neck, a, of the bladder the prostate projects in an arched form, and is transfixed by the instrument, d. The prostate may assume this appearance, as well from instruments having been forced against it, as from an abscess cavity formed in its substance having received, from time to time, a certain amount of the urine, and retained this fluid under the pressure of strong efforts, made to void the bladder while the vesical orifice was closed above.



Plate 61.—Figure 12.

Fig. 13, Plate 61.—The lateral lobes, d e, of the prostate are enlarged; and, occupying the position of the third lobe, appear as three masses, a b c, plicated upon each other, and directed towards the vesical orifice, which they close like valves. The prostatic urethra branches upwards into three canals, formed by the relative position of the parts, e, c, b, a, d, at the neck of the bladder. The ureters are dilated, in consequence of the regurgitation of the contents of the bladder during the retention which existed ..



Plate 61.—Figure 13.

Fig. 1, Plate 62, exhibits the lobes of the prostate greatly increased in size. The part, a b, girds irregularly, and obstructs the vesical outlet, while the lateral lobes, c d, encroach upon the space of the prostatic canal. The walls of the bladder are much thickened.



Plate 62.—Figure 1.

Fig. 2, Plate 62.—The three lobes, a, d, c, of the prostate are enlarged and of equal size, moulded against each other in such a way that the prostatic canal and vesical orifice appear as mere clefts between them. The three lobes are encrusted on their vesical surfaces with a thick calcareous deposit. The surface of the third lobe, a, which has been half denuded of the calcareous crust, b, in order to show its real character, appeared at first to be a stone impacted in the neck of the bladder, and of such a nature it certainly would seem to the touch, on striking it with the point of a sound or other instrument.



Plate 62.—Figure 2, 3.

Fig. 3, Plate 62, represents the prostate with its three lobes enlarged, and the prostatic canal and vesical orifice narrowed. The walls of the bladder are thickened, fasciculated, and sacculated; the two former appearances being caused by a hypertrophy of the vesical fibres, while the latter is in general owing to a protrusion of the mucous membrane between the fasciculi.

Fig. 4, Plate 62.—The prostate presents four lobes, a, b, c, d, each being of large size, and projecting far into the interior of the bladder, from around the vesical orifice which they obstruct. The bladder is thickened, and the prostatic canal is elongated. The urethra and the lobes of the prostate have been perforated by instruments, passed for the retention of urine which existed. A stricturing band, e, is seen to cross the membranous part of the canal.



Plate 62.—Figure 4, 5.

Fig. 5, Plate 62.—The prostate, a a, is greatly enlarged, and projects high in the bladder, the walls of the latter, b b, being very much thickened. The ureters, c, are dilated, and perforations made by instruments are seen in the prostate. The prostatic canal being directed almost vertically, and the neck of the bladder being raised nearly as high as the upper border of the pubic symphysis, it must appear that if a stone rest in the bas fond of the bladder, a sound or staff cannot reach the stone, unless by perforating the prostate; and if, while the staff occupies this position, lithotomy be performed, the incisions will not be required to be made of a greater depth than if the prostate were of its ordinary proportions. On the contrary, if the staff happen to have surmounted the prostate, the incision, in order to divide the whole vertical thickness of this body, will require to be made very deeply from the perinaeal surface, and this circumstance occasions what is termed a "deep perinaeum."

Fig. 6, Plate 62.—The lower half, c, b, f, of the prostate, having become the seat of abscess, appears hollowed out in the form of a sac. This sac is separated from the bladder by a horizontal septum, e e, the proper base of the bladder, g g. The prostatic urethra, between a e, has become vertical in respect to the membranous part of the canal, in consequence of the upward pressure of the abscess. The sac opens into the urethra, near the apex of the prostate, at the point c; and a catheter passed along the urethra has entered the orifice of the sac, the interior of which the instrument traverses, and the posterior wall of which it perforates. The bladder contains a large calculus, i. The bladder and sac do not communicate, but the urethra is a canal common to both. In a case of this sort it becomes evident that, although symptoms may strongly indicate either a retention of urine, or the presence of a stone in the bladder, any instrument taking the position and direction of d d, cannot relieve the one or detect the other; and such is the direction in which the instrument must of necessity pass, while the sac presents its orifice more in a line with the membranous part of the urethra than the neck of the bladder is. The sac will intervene between the rectum and the bladder; and on examination of the parts through the bowel, an instrument in the sac will readily be mistaken for being in the bladder, while neither a calculus in the bladder, nor this organ in a state of even extreme distention, can be detected by the touch any more than by the sound or catheter. If, while performing lithotomy in such a state of the parts, the staff occupy the situation of d d d, then the knife, following the staff, will open, not the bladder which contains the stone, but the sac, which, moreover, if it happen to be filled with urine regurgigated from the urethra, will render the deception more complete.



Plate 62.—Figure 6.

Fig. 7, Plate 62.—The walls, a a, of the bladder, appear greatly thickened, and the ureters, b, dilated. The sides, c c c, of the prostate are thinned; and in the prostatic canal are two calculi, d d, closely impacted. In such a state of the parts it would be impossible to pass a catheter into the bladder for the relief of a retention of urine, or to introduce a staff as a guide to the knife in lithotomy. If, however, the staff can be passed as far as the situation of the stone, the parts may be held with a sufficient degree of steadiness to enable the operator to incise the prostate upon the stone.



Plate 62.—Figure 7.



COMMENTARY ON PLATES 63 & 64.

DEFORMITIES OF THE URINARY BLADDER.—THE OPERATIONS OF SOUNDING FOR STONE, OF CATHETERISM AND OF PUNCTURING THE BLADDER ABOVE THE PUBES.

The urinary bladder presents two kinds of deformity—viz., congenital and pathological. As examples of the former may be mentioned that in which the organ is deficient in front, and has become everted and protruded like a fungous mass through an opening at the median line of the hypogastrium; that in which the rectum terminates in the bladder posteriorly; and that in which the foetal urachus remains pervious as a uniform canal, or assumes a sacculated shape between the summit of the bladder and the umbilicus. The pathological deformities are, those in which vesical fistulae, opening either above the pubes, at the perinaeum, or into the rectum, have followed abscesses or the operation of puncturing the bladder in these situations, and those in which the walls of the organ appear thickened and contracted, or thinned and expanded, or sacculated externally, or ridged internally, in consequence of its having been subjected to abdominal pressure while overdistended with its contents, and while incapable of voiding these from some permanent obstruction in the urethral canal.[Footnote] The bladder is liable to become sacculated from two causes—from a hernial protrusion of its mucous membrane through the separated fasciculi of its fibrous coat, or from the cyst of an abscess which has formed a communication with the bladder, and received the contents of this organ. Sacs, when produced in the former way, may be of any number, or size, or in any situation; when caused by an abscess, the sac is single, is generally formed in the prostate, or corresponds to the base of the bladder, and may attain to a size equalling, or even exceeding, that of the bladder itself. The sac, however formed, will be found lined by mucous membrane. The cyst of an abscess, when become a recipient for the urine, assumes after a time a lining membrane similar to that of the bladder. If the sac be situated at the summit or back of the bladder, it will be found invested by peritonaeum; but, whatever be its size, structure, or position, it may be always distinguished from the bladder by being devoid of the fibrous tunic, and by having but an indirect relation to the vesical orifice.

[Footnote: On considering these cases of physical impediments to the passage of urine from the vesical reservoir through the urethral conduit, it seems to me as if these were sufficient to account for the formation of stone in the bladder, or any other part of the urinary apparatus, without the necessity of ascribing it to a constitutional disease, such as that named the lithic diathesis by the humoral pathologists.

The urinary apparatus (consisting of the kidneys, ureters, bladder, and urethra) is known to be the principal emunctory for eliminating and voiding the detritus formed by the continual decay of the parts comprising the animal economy. The urine is this detritus in a state of solution. The components of urine are chemically similar to those of calculi, and as the components of the one vary according to the disintegration occurring at the time in the vital alembic, so do those of the other. While, therefore, a calculus is only as urine precipitated and solidified, and this fluid only as calculous matter suspended in a menstruum, it must appear that the lithic diathesis is as natural and universal as structural disintegration is constant and general in operation. As every individual, therefore, may be said to void day by day a dissolved calculus, it must follow that its form of precipitation within some part of the urinary apparatus alone constitutes the disease, since in this form it cannot be passed. On viewing the subject in this light, the question that springs directly is, (while the lithic diathesis is common to individuals of all ages and both sexes,) why the lithic sediment should present in the form of concrement in some and not in others? The principal, if not the sole, cause of this seems to me to be obstruction to the free egress of the urine along the natural passage. Aged individuals of the male sex, in whom the prostate is prone to enlargement, and the urethra to organic stricture, are hence more subject to the formation of stone in the bladder, than youths, in whom these causes of obstruction are less frequent, or than females of any age, in whom the prostate is absent, and the urethra simple, short, readily dilatable, and seldom or never strictured. When an obstruction exists, lithic concretions take place in the urinary apparatus in the same manner as sedimentary particles cohere or crystallize elsewhere. The urine becoming pent up and stagnant while charged with saline matter, either deposits this around a nucleus introduced into it, or as a surplus when the menstruum is insufficient to suspend it. The most depending part of the bladder is that where lithic concretions take place; and if a sacculus exist here, this, becoming a recipient for the matter, will favour the formation of stone.] [End Footnote]

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.



Plate 63,—Figure 1.

FIG. 2, Plate 63.—The prostate, 2, 3, is enlarged, and the middle lobe, 2, appears bending the prostatic canal to an almost vertical position, and obstructing the vesical orifice. The bladder, 1, 1, 1, is thickened; the ureters, 7, are dilated; and a large sac, 6, 6, projects from the base of the bladder backwards, and occupies the recto-vesical fossa. The sac, equal in size to the bladder, communicates with this organ by a small circular opening, 8, situated between the orifices of the ureters. The peritonaeum is reflected from the summit of the bladder to that of the sac. A catheter, 4, appears perforating the third lobe of the prostate, 2, and entering the sac, 5, through the base of the bladder, below the opening, 8. In a case of this kind, a catheter occupying the position 4, 5, would, while voiding the bladder through the sac, make it seem as if it really traversed the vesical orifice. If a stone occupied the bladder, the point of the instrument in the sac could not detect it, whereas, if a stone lay within the sac, the instrument, on striking it here, would give the impression as if it lay within the bladder.



Plate 63,—Figure 2.

FIG. 3, Plate 63.—The urethra being strictured, the bladder has become sacculated. In the bas fond of the bladder appears a circular opening, 2, leading to a sac of large dimensions, which rested against the rectum. In such a case as this, the sac, occupying a lower position than the base of the bladder, must first become the recipient of the urine, and retain this fluid even after the bladder has been evacuated, either voluntarily or by means of instruments. If, in such a state of the parts, retention of urine called for puncturation, it is evident that this operation would be performed with greater effect by opening the depending sac through the bowel, than by entering the summit of the bladder above the pubes.



Plate 63,—Figure 3, 4.

FIG. 4, Plate 63.—The vesical orifice is obstructed by two portions, 3, 4, of the prostate, projecting upwards, one from each of its lateral lobes, 6, 6. The bladder is thickened and fasciculated, and from its summit projects a double sac, 1, 2, which is invested by the peritonaeum.

FIG. 5, Plate 63.—The prostatic canal is constricted and bent upwards by the third lobe. The bladder is thickened, and its base is dilated in the form of a sac, which is dependent, and upon which rests a calculus. An instrument enters the bladder by perforating the third lobe, but does not come into contact with the calculus, owing to the low position occupied by this body.



Plate 63,—Figure 5.

FIG. 6, Plate 63.—Two sacs appear projecting on either side of the base of the bladder. The right one, 5, contains a calculus, 6; the left one, of larger dimensions, is empty. The rectum lay in contact with the base of the bladder between the two sacs.



Plate 63,—Figure 6.

FIG. 7, Plate 63.—Four calculi are contained in the bladder. This organ is divided by two septa, 2, 4, into three compartments, each of which, 1, 3, 5, gives lodgment to a calculus; and another, 6, of these bodies lies impacted in the prostatic canal, and becomes a complete bar to the passage of a catheter. Supposing lithotomy to be performed in an instance of this kind, it is probable that, after the extraction of the calculi, 6, 5, the two upper ones, 3, 1, would, owing to their being embedded in the walls of the bladder, escape the forceps.



Plate 63,—Figure 7.

FIG. 8, Plate 63.-Two large polypi, and many smaller ones, appear growing from the mucous membrane of the prostatic urethra and vesical orifice, and obstructing these parts. In examining this case during life by the sound, the two larger growths, 1, 2, were mistaken by the surgeon for calculi. Such a mistake might well be excused if they happened to be encrusted with lithic matter.



Plate 63,—Figure 8.

FIG. 9, Plate 63.—The base of the bladder, 8, 8, appears dilated into a large uniform sac, and separated from the upper part of the organ by a circular horizontal fold, 2, 2. The ureters are also dilated. The left ureter, 3, 4, opens into the sac below this fold, while the right ureter opens above it into the bladder. In all cases of retention of urine from permanent obstruction of the urethra, the ureters are generally found more or less dilated. Two circumstances combine to this effect—while the renal secretion continues to pass into the ureters from above, the contents of the bladder under abdominal pressure are forced regurgitating into them from below, through their orifices.



Plate 63,—Figure 9.

FIG. 1, Plate 64.—The bladder, 6, appears symmetrically sacculated. One sac, 1, is formed at its summit, others, 3, 2, project laterally, and two more, 5, 4, from its base. The ureters, 7, 7, are dilated, and enter the bladder between the lateral and inferior sacs.



Plate 64,—Figure 1.

Fig. 2, Plate 64.—The prostate is greatly enlarged, and forms a narrow ring around the vesical orifice. Through this an instrument, 12, enters the bladder. The walls of the bladder are thickened and sacculated. On its left side appear numerous sacs, 2, 3, 4, 5, 6, 7, 8, and on the inner surface of its right side appear the orifices of as many more. On its summit another sac is formed. The ureters, 9, are dilated.



Plate 64,—Figure 2.

FIG. 3, Plate 64.—The prostate is enlarged, its canal is narrowed, and the bladder is thickened and contracted. A calculus, 1, 2, appears occupying nearly the whole vesical interior. The incision in the neck of the bladder in lithotomy must necessarily be extensive, to admit of the extraction of a stone of this size.



Plate 64,—Figure 3.

FIG. 4, Plate 64.—The prostatic canal is contracted by the lateral lobes, 4, 5; resting upon these, appear three calculi, 1, 2, 3, which nearly fill the bladder. This organ is thickened and fasciculated. In cases of this kind, and that last mentioned, the presence of stone is readily ascertainable by the sound.



Plate 64,—Figure 4.

FIG. 5, Plate 64.—The three prostatic lobes are enlarged, and appear contracting the vesical orifice. In the walls of the bladder are embedded several small calculi, 2, 2, 2, 2, which, on being struck with the convex side of a sound, might give the impression as though a single stone of large size existed. In performing lithotomy, these calculi would not be within reach of the forceps.



Plate 64,—Figure 5.

FIG. 6, Plate 64.—Two sacculi, 4, 5, appear projecting at the middle line of the base of the bladder, between the vasa deferentia, 7, 7, and behind the prostate, in the situation where the operation of puncturing the bladder per anum is recommended to be performed in retention of urine.



Plate 64,—Figure 6.

FIG. 7, Plate 64.—A sac, 4, is situated on the left side of the bladder, 3, 3, immediately above the orifice of the ureter. In the sac was contained a mass of phosphatic calculus. This substance is said to be secreted by the mucous lining of the bladder, while in a state of chronic inflammation, but there seems nevertheless very good reason for us to believe that it is, like all other calculous matter, a deposit from the urine.



Plate 64,—Figure 7.

FIG. 8, Plate 64, represents, in section, the relative position of the parts concerned in catheterism. [Footnote] In performing this operation, the patient is to be laid supine; his loins are to be supported on a pillow; and his thighs are to be flexed and drawn apart from each other. By this means the perinaeum is brought fully into view, and its structures are made to assume a fixed relative position. The operator, standing on the patient's left side, is now to raise the penis so as to render the urethra, 8, 8, 8, as straight as possible between the meatus, a, and the bulb, 7. The instrument (the concavity of its curve being turned to the left groin) is now to be inserted into the meatus, and while being gently impelled through the canal, the urethra is to be drawn forwards, by the left hand, over the instrument. By stretching the urethra, we render its sides sufficiently tense for facilitating the passage of the instrument, and the orifices of the lacunae become closed. While the instrument is being passed along this part of the canal, its point should be directed fairly towards the urethral opening, 6*, of the triangular ligament, which is situated an inch or so below the pubic symphysis, 11. With this object in view, we should avoid depressing its handle as yet, lest its point be prematurely tilted up, and rupture the upper side of the urethra anterior to the ligament. As soon as the instrument has arrived at the bulb, its further progress is liable to be arrested, from these causes:—1st, This portion of the canal is the lowest part of its perinaeal curve, 3, 6, 8, and is closely embraced by the middle fibres of the accelerator urinae muscle. 2nd, It is immediately succeeded by the commencement of the membranous urethra, which, while being naturally narrower than other parts, is also the more usual seat of organic stricture, and is subject to spasmodic constriction by the fibres of the compressor urethrae. 3d, The triangular ligament is behind it, and if the urethral opening of the ligament be not directly entered by the instrument, this will bend the urethra against the front of that dense structure. On ascertaining these to be the causes of resistance, the instrument is to be withdrawn a little in the canal, so as to admit of its being readjusted for engaging precisely the opening in the triangular ligament. As this structure, 6, is attached to the membranous urethra, 6*, which perforates it, both these parts may be rendered tense, by drawing the penis forwards, and thereby the instrument may be guided towards and through the aperture. The instrument having passed the ligament, regard is now to be paid to the direction of the pelvic portion of the canal, which is upwards and backwards to the vesical orifice, 3, d, 3. In order that the point of the instrument may freely traverse the urethra in this direction, its handle, a, requires to be depressed, b c, slowly towards the perinaeum, and at the same time to be impelled steadily back in the line d, d, through the pubic arch, 11. If the third lobe of the prostate happen to be enlarged, the vesical orifice will accordingly be more elevated than usual. In this case, it becomes necessary to depress the instrument to a greater extent than is otherwise required, so that its point may surmount the obstacle. But since the suspensory ligament of the penis, 10, and the perinaeal structures prevent the handle being depressed beyond a certain degree, which is insufficient for the object to be attained, the instrument should possess the prostatic curve, c c, compared with c b.

[Footnote: It may be necessary for me to state that, with the exception of this figure (which is obviously a plan, but sufficiently accurate for the purposes it is intended to serve) all the others representing pathological conditions and congenital deformities of the urethra, the prostate, and the bladder, have been made by myself from natural specimens in the museums and hospitals of London and Paris.]



Plate 64,—Figure 8.

In the event of its being impossible to pass a catheter by the urethra, in cases of retention of urine threatening rupture, the base or the summit of the bladder, according as either part may be reached with the greater safety to the peritonaeal sac, will require to be punctured. If the prostate be greatly and irregularly enlarged, it will be safer to puncture the bladder above the pubes, and here the position of the organ in regard to the peritonaeum, 1, becomes the chief consideration. The shape of the bladder varies very considerably from its state of collapse, 3, 3, 5, to those of mediate, 3, 3, 2, 1, and extreme distention, 3, 3, 4. This change of form is chiefly effected by the expansive elevation of its upper half, which is invested by the peritonaeum. As the summit of the bladder falls below, and rises above the level of the upper margin of the pubic symphysis, it carries the peritonaeum with it in either direction. While the bladder is fully expanded, 4, there occurs an interval between the margin of the symphysis pubis and the point of reflexion of the peritonaeum, from the recti muscles, to the summit of the viscus. At this interval, close to the pubes, and in the median line, the trocar may be safely passed through the front wall of the bladder. The instrument should, in all cases, be directed downwards and backwards, h, h, in a line pointing to the hollow of the sacrum.



COMMENTARY ON PLATES 65 & 66.

THE SURGICAL DISSECTION OF THE POPLITEAL SPACE AND THE POSTERIOR CRURAL REGION.

On comparing the bend of the knee with the bend of the elbow, as evident a correspondence can be discerned between these two regions, as exists between the groin and the axilla.

Behind the knee-joint, the muscles which connect the leg with the thigh enclose the space named popliteal. When the integuments and subcutaneous substance are removed from this place, the dense fascia lata may be seen binding these muscles so closely together as to leave but a very narrow interval between them at the mesial line. On removing this fascia, B B M M, Plate 65, the muscles part asunder, and the popliteal space as usually described is thereby formed. This region now presents of a lozenge-shaped form, B J D K, of which the widest diameter, D J, is opposite the knee-joint. The flexor muscles, C D J, in diverging from each other as they pass down from the sides of the thigh to those of the upper part of the leg, form the upper angle of this space; whilst its lower angle is described by the two heads of the gastrocnemius muscle, E E, arising inside the flexors, from the condyles of the femur. The popliteal space is filled with adipose substance, in which are embedded several lymphatic bodies and through which pass the principal vessels and nerves to the leg.

In the dissection of the popliteal space, the more important parts first met with are the branches of the great sciatic nerve. In the upper angle of the space, this nerve will be found dividing into the peronaeal, I, and posterior tibial branches, H K. The peronaeal nerve descends close to the inner margin of the tendon, J, of the biceps muscle; and, having reached the outer side of the knee, I*, Plate 66, below the insertion of the tendon into the head of the fibula, winds round the neck of this bone under cover of the peronaeus longus muscle, S, to join the anterior tibial artery. The posterior tibial nerve, H K, Plate 65, descends the popliteal space midway to the cleft between the heads of the gastrocnemius; and, after passing beneath this muscle, to gain the inner side of the vessels, H*, Plate 66, it then accompanies the posterior tibial artery. On the same plane with and close to the posterior tibial nerve in the popliteal space, will be seen the terminal branch of the lesser sciatic nerve, together with a small artery and vein destined for distribution to the skin and other superficial parts on the back of the knee. Opposite the heads of the gastrocnemius, the peronaeal and posterior tibial nerves give off each a branch, both of which descend along the mesial line of the calf, and joining near the upper end of the tendo Achillis, the single nerve here, N, Plate 65, becomes superficial to the fascia, and thence descends behind the outer ankle to gain the external border of the foot, where it divides into cutaneous branches and others to be distributed to the three or four outer toes. In company with this nerve will be seen the posterior saphena vein, L, which, commencing behind the outer ankle, ascends the mesial line of the calf to join the popliteal vein, G, in the cleft between the heads of the gastrocnemius.

On removing next the adipose substance and lymphatic glands, we expose the popliteal vein and artery. The relative position of these vessels and the posterior tibial nerve, may now be seen. Between the heads of the gastrocnemius, the nerve, H, giving off large branches to this muscle, lies upon the popliteal vein, G, where this is joined by the posterior saphena vein. Beneath the veins lies the popliteal artery, F. On tracing the vessels and nerve from this point upwards through the popliteal space, we find the nerve occupying a comparatively superficial position at the mesial line, while the vessels are directed upwards, forwards, and inwards, passing deeply, as they become covered by the inner flexor muscles, C D, to the place where they perforate the tendon of the adductor magnus on the inner side of the lower third of the femur.

The popliteal artery, F, Plate 66, being the continuation of the femoral, extends from the opening in the great adductor tendon at the junction of the middle and lower third of the thigh, to the point where it divides, in the upper, and back part of the leg, at the lower border of the popliteus muscle, L, into the anterior and posterior tibial branches. In order to expose the vessel through this extent, we have to divide and reflect the heads of the gastrocnemius muscle, E E, and to retract the inner flexors. The popliteal artery will now be seen lying obliquely over the middle of the back of the joint. It is deeply placed in its whole course. Its upper and lower thirds are covered by large muscles; whilst the fascia and a quantity of adipose tissue overlies its middle. The upper part of the artery rests upon the femur, its middle part upon the posterior ligament of the joint, and its lower part upon the popliteus muscle. The popliteal vein, G; adheres to the artery in its whole course, being situated on its outer side above, and posterior to it below. The vein is not unfrequently found to be double; one vein lying to either side of the artery, and both having branches of communication with each other, which cross behind the artery. In some instances the posterior saphena vein, instead of joining the popliteal vein, ascends superficially to terminate in some of the large veins of the thigh. Numerous lymphatic vessels accompany the superficial and deep veins into the popliteal space, where they join the lymphatic bodies, which here lie in the course of the artery.

The branches derived from the popliteal artery are the muscular and the articular. The former spring from the vessel opposite those parts of the several muscles which lie in contact with it; the latter are generally five in number—two superior, two inferior, and one median. The two superior articular branches arise from either side of the artery, and pass, the one beneath the outer, the other beneath the inner flexors, above the knee-joint; and the two inferior pass off from it, the one internally, the other externally, beneath the heads of the gastrocnemius below the joint; while the middle articular enters the joint through the posterior ligament. The two superior and inferior articular branches anastomose freely around the knee behind, laterally, and in front, where they are joined by the terminal branches of the anastomotic, from the femoral, and by those of the recurrent, from the anterior tibial. The main vessel, having arrived at the lower border of the popliteus muscle, divides into two branches, of which one passes through the interosseous ligament to become the anterior tibial; while the other, after descending a short way between the bones of the leg, separates into the peronaeal and posterior tibial arteries. In some rare instances the popliteal artery is found to divide above the popliteus muscle into the anterior, or the posterior tibial, or the peronaeal.

The two large muscles, (gastrocnemius and soleus,) forming the calf of the leg, have to be removed together with the deep fascia in order to expose the posterior tibial, and peronaeal vessels and nerves. The fascia forms a sheath for the vessels, and binds them close to the deep layer of muscles in their whole course down the back of the leg. The point at which the main artery, F, Plate 66, gives off the anterior tibial, is at the lower border of the popliteus muscle, on a level with N, the neck of the fibula; that at which the artery again subdivides into the peronaeal, P, and posterior tibial branches, O, is in the mesial line of the leg, and generally on a level with the junction of its upper and middle thirds. From this place the two arteries diverge in their descent; the peronaeal being directed along the inner border of the fibula towards the back of the outer ankle; while the posterior tibial, approaching the inner side of the tibia, courses towards the back of the inner ankle. The gastrocnemius and soleus muscles overlie both arteries in their upper two thirds; but as these muscles taper towards the mesial line where they end in the tendo Achillis, V V, Plate 65, they leave the posterior tibial artery, O, with its accompanying nerve and vein, uncovered in the lower part of the leg, except by the skin and the superficial and deep layers of fasciae. The peronaeal artery is deeply situated in its whole course. Soon after its origin, it passes under cover of the flexor longus pollicis, R, a muscle of large size arising from the lower three fourths of the fibula, N, and will be found overlapped by this muscle on the outer border of the tendo Achillis, as low down as the outer ankle. The two arteries are accompanied by venae comites, which, with the short saphena vein, form the popliteal vein. The posterior tibial artery is closely followed by the posterior tibial nerve. In the popliteal space, this nerve crosses to the inner side of the posterior tibial artery, where both are about to pass under the gastrocnemius muscle, to which they give large branches. Near the middle of the leg, the nerve recrosses the artery to its outer side and in this relative position both descend to a point about midway between the inner ankle and calcaneum, where they appear having the tendons of the tibialis posticus and flexor longus digitorum to their inner side and the tendon of the flexor longus pollicis on their outer side. Numerous branches are given off from the nerve and artery to the neighbouring parts in their course.

The varieties of the posterior crural arteries are these—the tibial vessel, in some instances, is larger than usual, while the peronaeal is small, or absent; and, in others, the peronaeal supplies the place of the posterior tibial, when the latter is diminished in size. The peronaeal has been known to take the position of the posterior tibial in the lower part of the leg, and to supply the plantar arteries. In whatever condition the two vessels may be found, there will always be seen ramifying around the ankle-joint, articular branches, which anastomose freely with each other and with those of the anterior tibial.

The popliteal artery is unfavourably circumstanced for the application of a ligature. It is very deeply situated, and the vein adheres closely to its posterior surface. Numerous branches (articular and muscular) arise from it at short intervals; and these, besides being a source of disturbance to a ligature, are liable to be injured in the operation, in which case the collateral circulation cannot be maintained after the main vessel is tied. There is a danger, too, of injuring the middle branch of the sciatic nerve, in the incisions required to reach the artery; and, lastly, there is a possibility of this vessel dividing higher up than usual. Considering these facts in reference to those cases in which it might be supposed necessary to tie the popliteal artery—such cases, for example, as aneurism of either of the crural arteries, or secondary haemorrhages occurring after amputations of the leg at a time when the healing process was far advanced and the bleeding vessels inaccessible,—it becomes a question whether it would not be preferable to tie the femoral, rather than the popliteal artery. But when the popliteal artery itself becomes affected with aneurism, and when, in addition to the anatomical circumstances which forbid the application of a ligature to this vessel, we consider those which are pathological,—such as the coats of the artery being here diseased, the relative position of the neighbouring parts being disturbed by the tumour, and the large irregular wound which would be required to isolate the disease, at the risk of danger to the health from profuse suppuration, to the limb from destruction of the collateral branches, or to the joint from cicatrization, rendering it permanently bent,—we must acknowledge at once the necessity for tying the femoral part of the main vessel.

When the popliteal artery happens to be divided in a wound, it will be required to expose its bleeding orifices, and tie both these in the wound. For this purpose, the following operation usually recommended for reaching the vessel may be necessary. The skin and fascia lata are to be incised in a direction corresponding to that of the vessel. The extent of the incision must be considerable, (about three inches,) so as the more conveniently to expose the artery in its deep situation. On laying bare the outer margin of the semi-membranosus muscle, while the knee is straight, it now becomes necessary to flex the joint, in order that this muscle may admit of being pressed inwards from over the vessel. The external margin of the wound, including the middle branch of the sciatic nerve, should be retracted outwards, so as to ensure the safety of that nerve, while room is gained for making the deeper incisions. The adipose substance, which is here generally abundant, should now be divided, between the mesial line and the semimembranosus, till the sheath of the vessels be exposed. The sheath should be incised at its inner side, to avoid wounding the popliteal vein. The pulsation of the artery will now indicate its exact position. As the vein adheres firmly to the coats of the artery, some care is required to separate the two vessels, so as to pass the ligature around each end of the artery from without inwards, while excluding the vein. While this operation is being performed in a case of wound of the popliteal artery, the haemorrhage may be arrested by compressing the femoral vessel, either against the femur or the os pubis.

In the operation for tying the posterior tibial artery near its middle, an incision of three or four inches in extent is to be made through the skin and fascia, in a line corresponding with the inner posterior margin of the tibia and the great muscles of the calf. The long saphena vein should be here avoided. The origins of the gastrocnemius and soleus muscles require to be detached from the tibia, and then the knee is to be flexed and the foot extended, so as to allow these muscles to be retracted from the plane of the vessels. This being done, the deep fascia which covers the artery and its accompanying nerve is next to be divided. The artery will now appear pulsating at a situation an inch from the edge of the tibia. While the ligature is being passed around the artery, due care should be taken to exclude the venae comites and the nerve.

DESCRIPTION OF PLATES 65 & 66.

PLATE 65.

A. Tendon of the gracilis muscle.

B B. The fascia lata.

C C. Tendon of the semimembranosus muscle.

D. Tendon of the semitendinosus muscle.

E E. The two heads of the gastrocnemius muscle.

F. The popliteal artery.

G. The popliteal vein joined by the short saphena vein.

H. The middle branch of the sciatic nerve.

I. The outer (peronaeal) branch of the sciatic nerve.

K. The posterior tibial nerve continued from the middle branch of the sciatic, and extending to K, behind the inner ankle.

L. The posterior (short) saphena vein.

M M. The fascia covering the gastrocnemius muscle.

N. The short (posterior) saphena nerve, formed by the union of branches from the peronaeal and posterior tibial nerves.

O. The posterior tibial artery appearing from beneath the soleus muscle in the lower part of the leg.

P. The soleus muscle joining the tendo Achillis.

Q. The tendon of the flexor longus communis digitorum muscle.

R. The tendon of the flexor longus pollicis muscle.

S. The tendon of the peronaeus longus muscle.

T. The peronaeus brevis muscle.

U U. The internal annular ligament binding down the vessels, nerves, and tendons in the hollow behind the inner ankle.

V V. The tendo Achillis.

W. The tendon of the tibialis posticus muscle.

X. The venae comites of the posterior tibial artery.

PLATE 66.

A C D E F G H I indicate the same parts as in Plate 65.

B. The inner condyle of the femur.

K. The plantaris muscle lying upon the popliteal artery.

L. The popliteus muscle.

M M M. The tibia.

N N. The fibula.

O O. The posterior tibial artery.

P. The peronaeal artery.

Q R S T U V W. The parts shown in Plate 65.

X. The astragalus.



Plates 65, 66

COMMENTARY ON PLATES 67 & 68.

THE SURGICAL DISSECTION OF THE ANTERIOR CRURAL REGION, THE ANKLES, AND THE FOOT.

Beneath the integuments and subcutaneous adipose tissue on the fore part of the leg and foot, the fascia H H, Plate 67, Figure 2, is to be seen stretched over the muscles and sending processes between them, thus encasing each of these in a special sheath.

The fascia is here of considerable density. It is attached on the inner side of the leg to the spine of the tibia, D, Plate 67, Figure 2, and on the outer side it passes over the peronaeal muscles to those forming the calf. Between the extensor communis digitorum, B b, and the peronaeus longus, F, it sends in a strong process to be attached to the fibula, E. In front of the ankle joint, the fascia is increased in density, constituting a band (anterior annular ligament) which extends between the malleoli, forms sheaths for the several extensor tendons, and binds these down in front of the joint. From the lower border of the annular ligament, the fascia is continued over the dorsum of the foot, forming sheaths for the tendons and muscles of this part. Behind the inner malleolus, d, Plate 67, Figure 1, the fascia attached to this process and to the inner side of the os calcis appears as the internal annular ligament, which being broad and strong, forms a kind of arch, beneath which in special sheaths the flexor tendons, and the posterior tibial vessel and nerve, pass to the sole of the foot. On tracing the fascia from the front to the back of the leg, it will be seen to divide into two layers—superficial and deep; the former passes over the muscles of the calf and their common tendon (tendo Achillis) to which it adheres, while the latter passes between these muscles and the deep flexors. The deep layer is that which immediately overlies the posterior tibial and peronaeal vessels and nerves. While exposing the fascia on the forepart of the leg and dorsum of the foot, we meet with the musculo-cutaneous branch of the peronaeal nerve, which pierces the fascia at about the middle of the limb, and descends superficially in a direction between the fibula, and the extensor longus digitorum muscle, and after dividing into branches a little above the outer ankle, these traverse in two groups the dorsum of the foot, to be distributed to the integuments of the five toes. On the inner side of the tibia, D, Plate 67, Figure 1, will be seen the internal or long saphena vein, B B, which commencing by numerous branches on the dorsal surface of the foot ascends in front of the inner ankle, d, to gain the inner side of the leg, after which it ascends behind the inner side of the knee and thigh, till it terminates at the saphenous opening, where it joins the femoral vein. In its course along the lower part of the thigh, the leg and the foot, this vein is closely accompanied by the long saphenous nerve, derived from the anterior crural, and also by a group of lymphatics.

By removing the fascia from the front of the leg and foot, we expose the several muscles and tendons which are situated in these parts. In the upper part of the leg the tibialis anticus, A, Plate 67, Figure 2, and extensor-communis muscle, B, are adherent to the fascia which covers them, and to the intermuscular septum which divides them. In the lower part of the leg where these muscles and the extensor pollicis, C, terminate in tendons, a b c, they are readily separable from one another. The tibialis anticus lies along the outer side of the tibia, from which, and from the head of the fibula and interosseous ligament, it arises tendinous and fleshy. This muscle is superficial in its whole length; its tendon commencing about the middle of the leg, passes in a separate loose sheath of the annular ligament in front of the inner ankle, to be inserted into the inner side of the cuneiform bone and base of the metatarsal bone of the great toe. The extensor communis digitorum lies close to the outer side of the anterior tibial muscle, and arises from the upper three-fourths of the fibula, from the interosseous ligament and intermuscular septum. At the lower part of the leg, this muscle ends in three or four flat tendons, which pass through a ring of the annular ligament, and extending forwards, b b b b, over the dorsum of the foot, become inserted into the four outer toes. The peronaeus tertius or anterior, is that part of the common extensor muscle which is inserted into the base of the fifth metatarsal bone. On separating the anterior tibial and common extensor muscles, we find the extensor pollicis, C c, which, concealed between the two, arises from the middle of the fibula, and the interosseous ligament; its tendon passes beneath the annular ligament in front of the ankle joint, and after traversing the inner part of the dorsum of the foot, becomes inserted into the three phalanges of the great toe. Beneath the tendons of the extensor communis on the instep, will be seen the extensor digitorum brevis, K K, lying in an oblique direction, between the upper and outer part of the os calcis, from which it arises, and the four inner toes, into each of which it is inserted by a small flat tendon, which joins the corresponding tendon of the long common extensor.

The anterior tibial artery, L, Plate 67, Figure 2, extends from the upper part of the interosseous ligament which it perforates, to the bend of the ankle, whence it is continued over the dorsum of the foot. In the upper third of the leg, the anterior tibial artery lies deeply situated between the tibialis anticus, and flexor communis muscles. Here it will be found, close in front of the interosseous ligament, at about an inch and-a-half in depth from the anterior surface, and removed from the spine of the tibia at an interval equal to the width of the tibialis anticus muscle. In its course down the leg, the vessel passes obliquely from a point close to the inner side of the neck of the fibula, to midway between the ankles. In its descent, it becomes gradually more superficial. In the middle of the leg, the vessel passes between the extensor longus pollicis, and the tibialis anticus muscles. Above, beneath, and below the annular ligament, this artery will be found to pass midway between the extensor pollicis tendon, and those of the extensor communis, and to hold the same relation to these parts in traversing the dorsum of the foot, till it gains the interval between the two inner metatarsal bones, where it divides into two branches, one of which passes forwards in the first interdigital space, while the other sinks between the bones, to inosculate with the plantar arteries. The innermost tendon of the short common extensor crosses in front of the dorsal artery of the foot near its termination. Between the ankle and the first interosseous space the artery lies comparatively superficial, being here covered only by the skin and fascia and cellular membrane. Two veins accompany the anterior tibial artery and its continuation on the dorsum of the foot. The anterior tibial nerve, a branch of the peronaeal, joins the outer side of the artery, about the middle of the leg, and accompanies it closely in this position, till both have passed beneath the annular ligament. On the dorsum of the foot the nerve will be found to the inner side of the artery.

The branches of the anterior tibial artery are articular and muscular. From its upper end arises the recurrent branch which anastomoses in front of the knee with the articular branches of the popliteal artery. Near the ankle, arise on either side of the vessel two malleolar branches, internal and external, the former communicating with branches of the posterior tibial, the latter with those of the peronaeal. Numerous muscular branches arise, at short intervals, from the vessel in its passage down the leg. Tarsal, metatarsal, and small digital branches spring from the dorsal artery of the foot. The anterior tibial artery is rarely found to deviate from its usual course; in some cases it appears of less or of greater size than usual. When this vessel appears deficient, its place is usually supplied by some branch of the peronaeal or posterior tibial, which pierces the interosseous ligament from behind.

The anterior tibial artery when requiring a ligature to be applied to it in any part of its course, may be exposed by an incision, extending for three or four inches, (more or less, according to the depth of the vessel) along the outer border of the tibialis anticus muscle. The fibrous septum between this muscle and the extensor communis, will serve as a guide to the vessel in the upper third of the leg, where it lies deeply on the interosseous ligament. In the middle of the leg, the vessel is to be sought for between the anterior tibial and extensor longus pollicis muscles. In the lower part of the leg, and on the dorsum of the foot, it will be found between the extensor longus pollicis, and extensor communis tendons, the former being taken as a guide for the incision. In passing the ligature around this vessel at either of these situations, care is required to avoid including the venae comites and the accompanying nerve.

The sole of the foot is covered by a hard and thick integument, beneath which will be seen a large quantity of granulated adipose tissue so intersected by bands of fibrous structure as to form a firm, but elastic cushion, in the situations particularly of the heel and joints of the toes. On removing this structure, we expose the plantar fascia, B, Plate 68, Figure 1, extending from the os calcis, A, to the toes. This fascia is remarkably strong, especially its middle and outer parts, which serve to retain the arched form of the foot, and thereby to protect the plantar structures from superincumbent pressure during the erect posture. The superficial plantar muscles become exposed on removing the plantar fascia, to which they adhere. In the centre will be seen the thick fleshy flexor digitorum brevis muscle, B, arising from the inferior part of the os calcis, and passing forwards to divide into four small tendons, b b b b, for the four outer toes. On the inner side of the foot appears the abductor pollicis, D, arising from the inner side of the os calcis and internal annular ligament, and passing to be inserted with the flexor pollicis brevis, H, into the sesamoid bones and base of the first phalanx of the great toe. On the external border of the foot is situated the abductor minimi digiti, C, arising from the outer side of the os calcis, and passing to be inserted with the flexor brevis minimi digiti into the base of the first phalanx of the little toe. When the flexor brevis digitorum muscle is removed, the plantar arteries, L M, and nerves, are brought partially into view; and by further dividing the abductor pollicis, D, their continuity with the posterior tibial artery and nerves, K L, Plate 67, Figure 1, behind the inner ankle may be seen.

The plantar branches of the posterior tibial artery are the internal and external, both of which are deeply placed between the superficial and deep plantar muscles. The internal plantar artery is much the smaller of the two. The external plantar artery, L, Plate 68, Figure 1, is large, and seems to be the proper continuation of the posterior tibial. It corresponds, in the foot, to the deep palmar arch in the hand. Placed at first between the origin of the abductor pollicis and the calcaneum, the external plantar artery passes outwards between the short common flexor, B, and the flexor accessorius, E, to gain the inner borders of the muscles of the little toe; from this place it curves deeply inwards between the tendons of the long common flexor of the toes, F f f, and the tarso-metatarsal joints, to gain the outer side of the first metatarsal bone, H, Plate 68, Figure 2. In this course it is covered in its posterior half by the flexor brevis digitorum, and in its anterior half by this muscle, together with the tendons of the long flexor, F, Plate 68, Figure 1, of the toes and the lumbricales muscles, i i i i. From the external plantar artery are derived the principal branches for supplying the structures in the sole of the foot. The internal plantar nerve divides into four branches, for the supply of the four inner toes, to which they pass between the superficial and deep flexors. The external plantar nerve, passing along the inner side of the corresponding artery, sends branches to supply the outer toe and adjacent side of the next, and then passes, with the artery, between the deep common flexor tendon and the metatarsus, to be distributed to the deep plantar muscles.

The posterior tibial artery may be tied behind the inner ankle, on being laid bare in the following way:—A curved incision (the concavity forwards) of two inches in length, is to be made midway between the tendo Achillis and the ankle. The skin and superficial fascia having been divided, we expose the inner annular ligament, which will be found enclosing the vessels and nerve in a canal distinct from that of the tendons. Their fibrous sheath having been slit open, the artery will be seen between the venae comites, and with the nerve, in general, behind it.

When any of the arteries of the leg or the foot are wounded, and the haemorrhage cannot be commanded by compression, it will be necessary to search for the divided ends of the vessel in the wound, and to apply a ligature to both. The expediency of this measure must become fully apparent when we consider the frequent anastomoses existing between the collateral branches of the crural arteries, and that a ligature applied to any one of these above the seat of injury will not arrest the recurrent circulation through the vessels of the foot.

DESCRIPTION OF PLATES 67 & 68.

PLATE 67.

FIGURE 1. A. The tendon of the tibialis anticus muscle.

B B. The long saphena vein.

C C. The tendon of the tibialis posticus muscle.

D. The tibia; d, the inner malleolus.

E E. The tendon of the flexor longus digitorum muscle.

F. The gastrocnemius muscle; f, the tendo Achillis.

G. The soleus muscle.

H. The tendon of the plantaris muscle.

I I. The venae comites.

K K. The posterior tibial artery.

L L. The posterior tibial nerve.

FIGURE 2.

A. The tibialis anticus muscle; a, its tendon.

B. The extensor longus digitorum muscle; b b b b, its four tendons.

C C. The extensor longus pollicis muscle.

D D. The tibia.

E. The fibula; e, the outer malleolus.

F F. The tendon of the peronaeus longus muscle.

G G. The peronaeus brevis muscle; i, the peronaeus tertius.

H H. The fascia.

K. The extensor brevis digitorum muscle; k k, its tendons.

L L. The anterior tibial artery and nerve descending to the dorsum of the foot.



Plate 67, Figures 1, 2

PLATE 68.

FIGURE 1.

A. The calcaneum.

B. The plantar fascia and flexor brevis digitorum muscle cut; b b b, its tendons.

C. The abductor minimi digiti muscle.

D. The abductor pollicis muscle.

E. The flexor accessorius muscle.

F. The tendon of the flexor longus digitorum muscle, subdividing into f f f f, tendons for the four outer toes.

G. The tendon of the flexor pollicis longus muscle.

H. The flexor pollicis brevis muscle.

i i i i. The four lumbricales muscles.

K. The external plantar nerve.

L. The external plantar artery.

M. The internal plantar nerve and artery.

Plate 68, Figure 1

FIGURE 2.

A. The heel covered by the integument.

B. The plantar fascia and flexor brevis digitorum muscle cut; b b b, the tendons of the muscle.

C. The abductor minimi digiti.

D. The abductor pollicis.

E. The flexor accessorius cut.

F. The tendon of the flexor digitorum longus cut; f f f, its digital ends.

G. The tendon of the flexor pollicis.

H. The head of the first metatarsal bone.

I. The tendon of the tibialis posticus.

K. The external plantar nerve.

L L. The arch of the external plantar artery.

M M M M. The four interosseous muscles.

N. The external plantar nerve and artery cut.



Plate 68, Figure 2



CONCLUDING COMMENTARY. ON THE FORM AND DISTRIBUTION OF THE VASCULAR SYSTEM AS A WHOLE. ANOMALIES.—RAMIFICATION.—ANASTOMOSIS.

I.—The heart, in all stages of its development, is to the vascular system what the point of a circle is to the circumference—namely, at once the beginning and the end. The heart, occupying, it may be said, the centre of the thorax, circulates the blood in the same way, by similar channels, to an equal extent, in equal pace, and at the same period of time, through both sides of the body. In its adult normal condition, the heart presents itself as a double or symmetrical organ. The two hearts, though united and appearing single, are nevertheless, as to their respective cavities, absolutely distinct. Each heart consists again of two compartments—an auricle and a ventricle. The two auricles are similar in structure and form. The two ventricles are similar in the same respects. A septum divides the two auricles, and another—the two ventricles. Between the right auricle and ventricle, forming the right heart, there exists a valvular apparatus (tricuspid), by which these two compartments communicate; and a similar valve (bicuspid) admits of communication between the left auricle and ventricle. The two hearts being distinct, and the main vessels arising from each respectively being distinct likewise, it follows that the capillary peripheries of these vessels form the only channels through which the blood issuing from one heart can enter the other.

II.—As the aorta of the left heart ramifies throughout all parts of the body, and as the countless ramifications of this vessel terminate in an equal number of ramifications of the principal veins of the right heart, it will appear that between the systemic vessels of the two hearts respectively, the capillary anastomotic circulation reigns universal.

III.—The body generally is marked by the median line, from the vertex to the perinaeum, into corresponding halves. All parts excepting the main bloodvessels in the neighbourhood of the heart are naturally divisible by this line into equals. The vessels of each heart, in being distributed to both sides of the body alike, cross each other at the median line, and hence they are inseparable according to this line, unless by section. If the vessels proper to each heart, right and left, ramified alone within the limits of their respective sides of the body, then their capillary anastomosis could only take place along the median line, and here in such case they might be separated by median section into two distinct systems. But as each system is itself double in branching into both sides of the body, the two would be at the same time equally divided by vertical section. From this it will appear that the vessels belonging to each heart form a symmetrical system, corresponding to the sides of the body, and that the capillary anastomosis of these systemic veins and arteries is divisible into two great fields, one situated on either side of the median line, and touching at this line.

IV.—The vessels of the right heart do not communicate at their capillary peripheries, for its veins are systemic, and its arteries are pulmonary. The vessels of the left heart do not anastomose, for its veins are pulmonary, and its arteries are systemic. The arteries of the right and left hearts cannot anastomose, for the former are pulmonary, and the latter are systemic; and neither can the veins of the right and left hearts, for a similar reason. Hence, therefore, there can be, between the vessels of both hearts, but two provinces of anastomosis—viz., that of the lungs, and that of the system. In the lungs, the arteries of the right heart and the veins of the left anastomose. In the body generally (not excepting the lungs), the arteries of the left heart, and the veins of the right, anastomose; and thus in the pulmonary and the systemic circulation, each heart plays an equal part through the medium of its proper vessels. The pulmonary bear to the systemic vessels the same relation as a lesser circle contained within a greater; and the vessels of each heart form the half of each circle, the arteries of the one being opposite the veins of the other.

V.—The two hearts being, by the union of their similar forms, as one organ in regard to place, act, by an agreement of their corresponding functions, as one organ in respect to time. The action of the auricles is synchronous; that of the ventricles is the same; that of the auricles and ventricles is consentaneous; and that of the whole heart is rhythmical, or harmonious—the diastole of the auricles occurring in harmonical time with the systole of the ventricles, and vice versa. By this correlative action of both hearts, the pulmonary and systemic circulations take place synchronously; and the phenomena resulting in both reciprocate and balance each other. In the pulmonary circulation, the blood is aerated, decarbonized, and otherwise depurated; whilst in the systemic circulation, it is carbonized and otherwise deteriorated.

VI.—The circulation through the lungs and the system is carried on through vessels having the following form and relative position, which, as being most usual, is accounted normal. The two brachio-cephalic veins joining at the root of the neck, and the two common iliac veins joining in front of the lumbar vertebrae, form the superior and inferior venae cavae, by which the blood is returned from the upper and lower parts of the body to the right auricle, and thence it enters the right ventricle, by which it is impelled through the pulmonary artery into the two lungs; and from these it is returned (aerated) by the pulmonary veins to the left auricle, which passes it into the left ventricle, and by this it is impelled through the systemic aorta, which branches throughout the body in a similar way to the systemic veins, with which the aortic branches anastomose generally. On viewing together the system of vessels proper to each heart, they will be seen to exhibit in respect to the body a figure in doubly symmetrical arrangement, of which the united hearts form a duplex centre. At this centre, which is the theatre of metamorphosis, the principal abnormal conditions of the bloodvessels appear; and in order to find the signification of these, we must retrace the stages of development.

VII.—From the first appearance of an individualized centre in the vascular area of the human embryo, that centre (punctum saliens) and the vessels immediately connected with it, undergo a phaseal metamorphosis, till such time after birth as they assume their permanent character. In each stage of metamorphosis, the embryo heart and vessels typify the normal condition of the organ in one of the lower classes of animals. The several species of the organ in these classes are parallel to the various stages of change in the human organ. In its earliest condition, the human heart presents the form of a simple canal, similar to that of the lower Invertebrata, the veins being connected with its posterior end, while from its anterior end a single artery emanates. The canal next assumes a bent shape, and the vessels of both its ends become thereby approximated. The canal now being folded upon itself in heart-shape, next becomes constricted in situations, marking out the future auricle and ventricle and arterial bulb, which still communicate with each other. From the artery are given off on either side symmetrically five branches (branchial arches), which arch laterally from before, outwards and backwards, and unite in front of the vertebrae, forming the future descending aorta. In this condition, the human heart and vessels resemble the Piscean pipe. The next changes which take place consist in the gradual subdivision, by means of septa, of the auricle and ventricle respectively into two cavities. On the separation of the single auricle into two, while the ventricle as yet remains single, the heart presents that condition which is proper to the Reptilian class. The interauricular and interventricular septa, by gradual development from without inwards, at length meet and coalesce, thereby dividing the two cavities into four—two auricles and two ventricles—a condition proper to the Avian and Mammalian classes generally. In the centre of the interauricular septum of the human heart, an aperture (foramen ovale) is left as being necessary to the foetal circulation. While the septa are being completed, the arterial bulb also becomes divided by a partition formed in its interior in such a manner as to adjust the two resulting arteries, the one in connexion with the right, the other with the left ventricle. The right ventricular artery (pulmonary aorta) so formed, has assigned to it the fifth (posterior) opposite pair of arches, and of these the right one remaining pervious to the point where it gives off the right pulmonary branch, becomes obliterated beyond this point to that where it joins the descending aorta, while the left arch remains pervious during foetal life, as the ductus arteriosus still communicating with the descending aorta, and giving off at its middle the left pulmonary branch. The left ventricular artery (systemic aorta) is formed of the fourth arch of the left side, while the opposite arch (fourth right) is altogether obliterated. The third and second arches remain pervious on both sides, afterwards to become the right and left brachio-cephalic arteries. The first pair of arches, if not converted into the vertebral arteries, or the thyroid axes, are altogether metamorphosed. By these changes the heart and primary arteries assume the character in which they usually present themselves at birth, and in all probability the primary veins corresponded in form, number, and distribution with the arterial vessels, and underwent, at the same time, a similar mode of metamorphosis. One point in respect to the original symmetrical character of the primary veins is demonstrable—namely, that in front of the aortic branches the right and left brachio-cephalic veins, after joining by a cross branch, descend separately on either side of the heart, and enter (as two superior venae cavae) the right auricle by distinct orifices. In some of the lower animals, this double condition of the superior veins is constant, but in the human species the left vein below the cross branch (left brachio-cephalic) becomes obliterated, whilst the right vein (vena cava superior) receives the two brachio-cephalic veins, and in this condition remains throughout life. After birth, on the commencement of respiration, the foramen ovale of the interauricular septum closes, and the ductus arteriosus becomes impervious. This completes the stages of metamorphosis, and changes the course of the simple foetal circulation to one of a more complex order—viz., the systemic-pulmonary characteristic of the normal state in the adult body.

VIII.—Such being the phases of metamorphosis of the primary (branchial) arches which yield the vessels in their normal adult condition, we obtain in this history an explanation of the signification not only of such of their anomalies as are on record, but of such also as are potential in the law of development; a few of them will suffice to illustrate the meaning of the whole number:—lst, The interventricular as well as the interauricular septum may be arrested in growth, leaving an aperture in the centre of each; the former condition is natural to the human foetus, the latter to the reptilian class, while both would be abnormal in the human adult. 2nd. The heart may be cleft at its apex in the situation of the interventricular septum—a condition natural to the Dugong, A similar cleavage may divide the base of the heart in the situation of the interauricular septum. 3rd. The partitioning of the bulbus arteriosus may occur in such a manner as to assign to the two aortae a relative position, the reverse of that which they normally occupy—the pulmonary aorta springing from the left ventricle and the systemic aorta arising from the right, and giving off from its arch the primary branches in the usual order. [Footnote 1] 4th. As the two aortae result from a division of the common primary vessel (bulbus arteriosus), an arrest in the growth of the partition would leave them still as one vessel, which (supposing the ventricular septum remained also incomplete) would then arise from a single ventricle. 5th. The ductus arteriosus may remain pervious, and while co-existing with the proper aortic arch, two arches would then appear on the left side. 6th. The systemic normal aortic arch may be obliterated as far up as the innominate branch, and while the ductus arteriosus remains pervious, and leading from the pulmonary artery to the descending part of the aortic arch, this vessel would then present the appearance of a branch ascending from the left side and giving off the brachio-cephalic arteries. The right ventricular artery would then, through the medium of the ductus arteriosus, supply both the lungs and the system. Such a state of the vessels would require (in order that the circulation of a mixed blood might be carried on) that the two ventricles freely communicate. 7th. If the fourth arch of the right side remained pervious opposite the proper aortic arch, there would exist two aortic arches placed symmetrically, one on either side of the vertebral column, and, joining below, would include in their circle the trachea and oesophagus. 8th. If the fifth arch of the right side remained pervious opposite the open ductus arteriosus, both vessels would present a similar arrangement, as two symmetrical ducti arteriosi co-existing with symmetrical aortic arches. 9th. If the vessels appeared co-existing in the two conditions last mentioned, they would represent four aortic arches, two on either side of the vertebral column. 10th. If the fourth right arch, instead of the fourth left (aorta), remained pervious, the systemic aortic arch would then be turned to the right side of the vertebral column, and have the trachea and oesophagus on its left. 11th. When the bulbus arteriosus divides itself into three parts, the two lateral parts, in becoming connected with the left ventricle, will represent a double ascending systemic aorta, and having the pulmonary artery passing between them to the lungs. 12th. When of the two original superior venae cavae the right one instead of the left suffers metamorphosis, the vena cava superior will then appear on the left side of the normal aortic arch. [Footnote 2] Of these malformations, some are rather frequently met with, others very seldom, and others cannot exist compatible with life after birth. Those which involve a more or less imperfect discharge of the blood-aerating functions of the lungs, are in those degrees more or less fatal, and thus nature aborting as to the fitness of her creation, cancels it.