" On the 3d April, when I examined the case, I found the cornea slightly nebulous, the eye free from inflammation and pain, and the ap pearances and movements of the animal exactly such as described by Mr. Logan. When the patient kept her head at rest, as she sat before me, in a moderate light, the animal covered the two lower thirds of the pupil. Watching it carefully, its cystic portion was seen to be come more or less spherical, and then to assume a flattened form, while its head I saw at one moment thrust suddenly down to the bottom of the anterior chamber, and at the next drawn up so completely as scarcely to be visible. Mr. Meikle turned the child's head gently back, and instantly the hydatid revolved through the aqueous humour, so that the head fell to the upper edge of the cornea, now become the more depending part. On the child again leaning forwards, it settled like a little balloon in its former 'position, preventing the patient from seeing objects directly before her, or below the level of the eye, but permitting the vision of such as were placed above. Mr. Logan had observed no increase of size in the animal while it was under his inspection. Mr. Meikle had watched it carefully for three weeks without observing any other change than a slight increase in the opacity of the cystic portion.
" To every one who had seen or heard of Mr. Logan's case, the question naturally occurred, Ought not this animal to be removed from the eye? Mr. Logan and Mr. Meikle appeared to have deferred employing any means for destroy ing or removing it ; first, because it seemed to be producing no mischief: and, secondly, be cause there was a probability that it was a short-lived animal, and likely therefore speedily to perish and shrink away, so as to give no greater irritation than a shred of lenticular capsule. Various means naturally suggested themselves for killing the animal, such as passing electric or galvanic shocks through the eye, rubbing in oil of turpentine round the orbital region, giving this medicine internally in small doses, or putting the child on a course of sulphate of quina, or some other vegetable bitter known to be inimical to the life of the Entozoa. As the patient appeared to be in perfect health, it was natural to suppose that the other organs were free from hydatids, and that a change of diet would have little or no effect upon the solitary individual in the aque ous humour. Ilad she, on the contrary, pre sented a cachectic constitution, with pale com plexion, tumid belly, debility, and fever, none of which symptoms were present, we should have been led to suspect that what was visible in the eye was but a sample of innumerable hydatids in the internal parts of the body, and might have recommended a change of diet, with some hopes of success. In the course of six weeks after I saw the patient, the cysticercus having enlarged in size, the vessels of the con junctiva and sclerotica became turgid, the iris changed in colour, and less free in its motions, while the child complained much of pain in the eye; it was decided that the operation of ex traction should be attempted, and I owe to Dr. Robertson of Edinburgh, who operated, the communication of the following particulars. The incision of the cornea was performed with out the slightest difficulty, but no persuasion or threats could induce the child again to open the eye; she became perfectly unruly, and the muscles compressed the eye-ball so powerfully that the lens was forced out, and the hydatid ruptured. The patient was put to bed in this state. In the evening Dr. R. succeeded in getting the girl to open the eyelids, when with the forceps he extracted from the lips of the incision the remains of the animal in shreds, it being so delicate as scarcely to bear the slightest touch. A portion of the iris remained
in the wound, which nothing would induce the girl to allow Dr. R. to attempt to return.
"After the eye healed, the cornea remained clear, except at the cicatrice, where it was only semitransparent; the pupil, in consequence of adhesion to the cicatrice, was elliptical, and the opaque capsule of the lens occupied the pu pillary aperture. The patient readily recog nized the presence of light." The Cysticercus cellulose occurs also in quadrupeds, and is found most commonly and in greatest abundance in the Bog, giving rise to that state of the muscles which is called " measly pork." Of the Cestoid Order of Entozoa two species belonging to different genera infest the Hu man Body. The Swiss and Russians are troubled with the Bothriocepholus lotus; the English, Dutch, and Germans with the •Thnta solium: both kinds occur, but not simulta neously in the same individual, in the French. It is not in our province to dwell upon the medical remedies for these parasites, but we may observe that the old vermifuge mentioned by Celsus, viz. the bark of the pomegranate, is equally efficacious and safer perhaps than the oleum tcrebinthing commonly employed in this country for the expulsion of the Tape-worm.
From the singular geographical distribution, as it may be termed, of the above Cestoid parasites, the 13othriorepholus lulus rarely falls under the observation of the English Entozoo logist. It may be readily distinguished from the Teenia solium by the form of the segments, which are broader than they are long, and by the position of the genital pores. which occur in a series along the middle of one of the flat tened surfaces of the body, and not at the mar gin of each segment as in the Tenia solium. The head, which was for a long time a deside ratum in natural history, has at length been dis covered by Bremser. It is of an elongated form, two-thirds of a line in length, and presents, in stead of the four round oscula characteristic of the true Tend.; two lateral longitudinal fosses, or bothria, (a a,fig. 62, which is a highly-magnified view of the head of the Bothrioce pholus lotus.) The Tenia solium (fig. 63) attains the length of from four to ten feet, and has been ob served to extend from the pylo rus to within seven inches of the anus of the human intes tine.* Its breadth varies from one-fourth of a line at its an terior part to three or four lines towards the posterior part of the body, which then again diminishes. The head is small, and generally hemispherical, broader than long, and often as if truncated anteriorly ; the four mouths, or oscula, are situated on the anterior surface, (a, fig. 63,) and surround the central rostellum, which is very short, termi nated by a minute apical papilla, and surround ed by a double circle of small recurved hooks. The segments of the neck, or anterior part of the body, are represented by transverse rugre, the marginal angles of which scarcely project be yond the lateral line ; the succeeding seg ments are subquadrate, their length scarcely exceeding their breadth, they then become sen sibly longer, narrower anteriorly, thicker and broader at the posterior margin, which slightly overlaps the succeeding joint ; the last series of segments are sometimes twice or three times as long as they are broad. The generative orifices (b, b) are placed near the middle of one of the margins of each joint, and are generally alter nate.