With respect to the following parasite of the human body, the Spiroptera tlominis, Rud., considerable obscurity prevails. A poor wo man, who is still living in the workhouse of the parish of St. Sepulchre, London, has been subject, since the year 1806, (when she was twenty-four years old,) up to the present time, to retention of urine, accompanied with dis tress and pain indicative of disease of the bladder. The catheter has been employed from time to time during this long period to draw off the urine, and its application has been, and continues occasionally to be, followed by the extraction and subsequent discharge of worms, or vermiform substances, with nume rous small granular bodies. The latter are of uniform size, resembling small grains of sand : those which we have examined, and which were preserved in spirit, present a subglebular, or irregularly flattened form ; but when recently expelled, I am assured by my friend Dr. Arthur Farre, that they are perfectly spherical ; they consist of an external smooth, firm, dia phanous coat, including a compact mass of brown and minutely granular substance. The inner surface of the containing capsule pre sents, under the microscope, a regular, beau tiful, and minute reticulation, produced by depressions or cells of a hexagonal form. These, therefore, we regard as ova, and not as fortuitous morbid productions' The vcrmi form substances are elongated bodies of a moderately firm, solid, homogeneous texture, varying in length from four to eight inches ; attenuated at both extremities; having the diameter of a line half-way between the ex tremities and the middle part, where the body is contracted and abruptly bent upon itself. Some are irregularly trigonal, others tetragonal. In the three-sided specimens one surface is broad, convex, and smooth ; the other two are narrow and concave, and separated by a nar row longitudinal groove, in which is sometimes lodged a filamentary brown concretion. In the tetragonal portions the broad smooth sur face is divided into two parts by the rising of the middle part of the convexity into an angle. The most remarkable appearance in these am biguous productions is the beautiful crenation of one of the angles or ridges between the convex and concave facet; which, from its regularity and constancy, can hardly be ac counted for on the theory of their nature and origin suggested by Rudolphi: ' lytnphamque in canalibus fistulosis coactam passiinque corn prcssam filum inivquale efformare On the other hand it is equally difficult to form any satisfactory notion of these substances as organized bodies growing by an inherent and independent vitality. We have not been able to observe a single example in which the substance had both extremities well defined and unbroken ; these, on the contrary, are flattened, membranous, and more or less jagged and irregular. They present no trace of ali mentary or generative orifices on any part of their exterior surface, nor any canals subser vient to those functions, in the interior paren chyma. If subsequent observations on re cently expelled specimens of these most curious and interesting productions should, however, establish their claims to be regarded as Entozoa, they will probably rank as a sim ple form of Sterelmintha.* The existence of the Spiroptera Ifominis is founded on the observation of substances very different from the preceding productions. The specimens so called were transmitted to Itu dolphi, in a separate phial, at the same time with the ova and larger parenchymatous bodies above described, and are presumed to have been expelled from the same female under the same circumstances. They consisted of six small Nematoid worms of different sexes ; the males (fig. 70*) were eight, the females ten lines in length, slender, white, highly elastic.
The head (a, fig. 70) truncated, and with one or two papilla:: the mouth orbicular, the body attenuated at both extremities, but espe cially anteriorly. The tail in the female thicker, and with a short obtuse apex; that of the male more slender, and emitting a small mesial tubules (c), probably the sheath of the penis : a dermal aliform production near the same extremity determines the reference of this Entozoon to the genus Spiroptera.
There are no specimens of this Entozoon among the substances discharged from the urethra of the female, whose case is above alluded to, which are preserved in the Museum of the College of Surgeons.
The following parasite of the urinary appa ratus, concerning which no obscurity or doubt prevails, is the Strongylus gigas (fig. 71), the giant not only of its genus but of the whole class of cavitary worms. This species is de veloped in the parenchyma of the kidney itself, and occasionally attains the length of three feet, with a diameter of half an inch. A worm of nearly this magnitude, which oc cupied the entire capsule of the left kidney, of the parenchyma of which it had occasioned the total destruction, is preserved in the collec tion of the Royal College of Surgeons.
The male Strongylus gigas is less than the female, and is slightly attenuated at both ex tremities. The head (a) is obtuse, the mouth orbicular, and surrounded by six hemispherical papillae (A); the body is slightly impressed with circular stria, and with two longitudinal impressions ; the tail is incurved in the male, and terminated by a dilated pouch orbursu, from the base of which the single intromittent spi culum (b) projects. In the female the caudal extremity is less attenuated and straighter, with the anus (c) a little below the apex : the vulva (d,fig. 95) is situated at a short distance from the anterior extremity.
The Strongylus gigas is not confined to the Duman Subject, but more frequently infests the kidney of the Dog, Wolf, Otter, Raccoon, Glutton, Horse, and Bull. It is generally of a dark blood-colour, which seems to be owing to the nature of its food, which is derived from the vessels of the kidney, as, where suppuration has taken place around it, the worm has been found of a whitish hue.
The Round-worm (Ascaris Lumbrieoides, Linn.) (fi,g. 7.2) is the first described' and most common of the Human Entozoa, and is that which has been subjected to the most repeated, minute, and successful anatomical examinations. It is found in the intestines of Nan, the flog, and the Ox. In the Human subject the round worms are much more com mon in children than in adults, and are ex tremely rare in aged persons. They are most obnoxious to individuals of the lymphatic tem perament, and such as use gross and indi gestible food, or who inhabit low and damp localities. They generally occur in the small intestines.
The body is round, elastic, with a smooth shining surface, of a whitish or yellowish colour ; atte nuated towards both extremities, but chiefly towards the anterior one (a,fig.72), which commences abruptly by three tubercles which surround the mouth, and charac terize the genus. The posterior extremity (b) terminates in an ob tuse point, at the apex of which a small black point may frequently be observed. In the female this extremity is straighter and thicker than in the male, in which it is terminated more acutely, and is abruptly curved towards the ventral side of the body. The anus is situated in both sexes close to the extremity of the tail, in form like a transverse fissure. In the female the body generally presents a con striction at the junction of the an terior with the middle third (c) in which the vulva (d) is situated.
The body of the Ascaris lumbri coides is transversely furrowed with numerous very fine striw, and is marked with four longitudinal equi distant lines extending from the head to the tail. These lines are independent of the exterior enve lope, which simply covers them ; two are lateral, and are larger than the others, which are dorsal and ventral. The lateral lines com mence on each side the mouth, but, from their extreme fineness, can with difficulty be perceived ; they slightly enlarge as they pass downwards to about one-third of a line in diameter in large speci mens, and then gradually diminish to the sides of the caudal extremi ty. They are occasionally of a red colour, and denote the situation of the principal vessels of the body. The dorsal and abdominal longitu dinal lines (e, 72) are less marked than the preceding, and by no means widen in the same proportion at the middle of the body. They correspond to the two nervous chords, hereafter to be described.