cies of tape worm, which is perhaps owing to the circumstance that the longitudinal fibres entering into its composition are continued from one segment to the other, in stead of being, as in the Tania, distinct in each articulation. It inhabits the small intestines, in which as many as three or four are often found to co-exist. The people amongst whom they occur most frequently are the Russians, Poles, and Swiss. In the French they are as common as the Tania, but they are rarely met with in England.

The symptoms which they occasion, and the treatment necessary for their removal, are similar to those of the Tania.

8. Polystoma pinguicola,

(from Toλus, many, and σropa, stomach.) The body of this species of Polystoma is flat, truncated anteriorly, and pointed at the posterior extremity. On the under

side of the head there are six orbicular

pores disposed in a semilunar form. A large suctorious cavity exists on the ventral aspect, and a small orifice is situated at the apical extremity. This parasite has

A

serous cysts, that it is not impossible that this body was nothing more than coagulated albumen, the orbicular pores being only small accidental openings in it.

A second species of Polystoma, the Polystoma venarum, is also mentioned by Treutler. It was found in the saphena vein of a man, which was accidentally ruptured while bathing, and is generally supposed to have been a non-parasitic worm belonging to a species of Planaria, and to have been introduced accidentally into this strange situation.

9. Distoma hepaticum, or Liver Fluke.

The form of the Distoma hepaticum is oval, flattened, and elongate. It measures generally from one to five lines in length, and from half a line to a line in width. The anterior pore, or mouth, is round and small; the posterior cavity, which is imperforate, and subservient only to adhesion and locomotion, is large, transversely oval, and situated on the ventral surface of the body in the anterior half. From the anterior pore proceeds a short wide tube, the oesophagus, which terminates in two nutrient canals, which run along the centre of the animal to the opposite end, sending off from their outer

B

Polystoma pinguicola.

A, Polystoma in situ.

B, Natural size.-b, Suctorious cavity. C, Head, shewing the six pores.

only been found once in the human body. Treutler, a German, discovered it in a small tumor about the size of a hazel-nut, situated in the adipose tissue connected with the left ovary of a young woman who had died in child-bed. The tumor, which appeared to consist of indurated fat, was of a reddish colour, and hollow within.

Cruveilhier questions, and I think with good reason, whether the body found by Treutler was really a parasitic worm. In the first place, the ovary is not surrounded by fat; and it is somewhat surprising that this most curious animal should only have been seen by one individual. Besides, loose albuminous bodies are so often found floating free in ovarian and other

Distoma hepaticum; natural size.

a, Mouth.-b, Genital pore.-e, Nutrient canals.

sides cæcal branches or processes, but have no anal outlet. Between the two pores already described there is a third orifice, exclusively destined, like the opening on each joint of the Tænia, to the generative system; and from which there is generally protruded, in the full-sized specimens, a small tubular process.

The Distoma hepaticum inhabits the gallbladder and biliary ducts, and appears to derive its nutriment from the bile. In the liver of a sheep which I lately dissected, the biliary ducts containing these animals were much enlarged, some of them being capable of admitting the little finger; and the surrounding tissue was atrophied. Cruveilhier states that he has found the ducts cartilaginous, and even ossified, in animals affected with them. This worm very rarely infests the human species; in

communicated from one individual to another; and Lind and other writers are of opinion that Europeans, on visiting the countries where it exists, become affected with it by contact with the negroes. In America it is said to make its appearance almost exclusively amongst the negroes, and chiefly in those who are newly arrived from Africa. We occasionally meet with it in this country, in individuals who have recently returned from the tropics. There is a specimen in the museum of the College of Surgeons, twenty-two inches in length, which was extracted from the leg of a boy who was a patient of the late Sir W. Blizard, at this hospital. We have also a worm in the museum, removed by Mr. Headington, who was formerly surgeon of this hospital, from the leg of a sailor, where it had been imbedded for two years; and there was another patient in the hospital at the same time, likewise affected in this way. From some observations by Sir James Macgrigor, it would appear that the disorder originating in these worms prevails at times in an epidemic form. Thus he mentions that some troops having embarked, after a residence of two months at Bombay, were attacked whilst at sea so generally, that out of three hundred and sixty as many as one hundred and sixty-one became affected with it. Clot Bey, a French surgeon, in the service of the Pacha of Egypt, mentions that he has seen as many as a hun dred patients, labouring under Guinea worm, in hospital at one time. Little seems to be known which can account for the development of this parasite, though authors have speculated abundantly on the subject. It has been noticed, however, that it occurs much less frequently amongst the officers than the common soldiers, and those who occasionally lie on the ground, or go about with their feet and arms naked.

The Guinea worm may remain imbedded beneath the skin for many months, without occasioning any inconvenience, but sooner or later it excites irritation and inflammation in the structures around, which vary in severity according to the constitution of the individual, and the situation and size of the worm. The symptoms commence in a formicating sensation or uneasiness under the skin, accompanied with a superficial cord-like elevation on the surface. A phlysaceous vesicle or pustule forms, which bursting, gives exit at a circular aperture, either immediately or after suppurating for a day or two, to the head of the worm. These local symptoms are preceded usually by slight derangement of the system generally, When situated about the fingers or toes, the worm is often productive of much suffering, and is with difficulty got rid of.

When deeply seated it sometimes causes considerable fever, great swelling, and tedious abscesses and sinuses, giving out a serous ill-conditioned discharge for many months without the worm making its appearance.

The treatment consists in the cautious and gradual extraction of the worm, special care being taken to avoid breaking it across, as this accident is liable to be followed by an aggravation of the inflammation, and the formation of sinuses in its course, together with great constitutional disturbance. These unfavourable effects are attributed, by Hunter, to the contact of dead animal matter, with a large extent of living surface, to which it now bears the relation of a foreign body; such violent symptoms being rarely seen so long as the dracunculus is alive and uninjured. When the worm protrudes, it should be laid hold of and gently drawn out from its resting place as far as possible. The part removed should then be secured at the aperture with a strip of plaster, or tied to a piece of stick, and the traction may be repeated once or twice in twenty-four hours until the entire worm is brought away—a process often requiring many days, or even a month, for its completion. Some surgeons recommend cutting down upon the middle of the animals, and by pulling simul. taneously at both ends, shortening the period requisite for the removal of the dracunculus-a plan which is practised by the native Indians. When the worm is got rid of, the sinus usually closes readily. The use of internal remedies and external applications do not appear to be of any essential service. Sir James Macgrigor found that the extension of this affection amongst the troops was checked by requir ing great attention in regard to cleanliness, and separating the soldiers troubled with these worms from those that were free from them.

11. Filaria Oculi.

The discovery of a species of Folaria in the interior of the human eye, we owe to Dr. Nordmann of Odessa. On examining an opaque crystalline lens, extracted by Baron von Gräfe, and partially covered by its capsule, he detected in the liquor Morgagni two very small and delicate rings, which, with the aid of a microscope, he recognised as convoluted Filariæ. One of them had been wounded, probably by the instrument used for opening the capsule, and the intestinal canal was seen protruding at the rupture. The other was entire, about three quarters of a line long, and through the transparent integument could be seen a straight intestinal canal surrounded by convolutions of the oviducts. In a lens extracted by Dr. Jungken, Dr. Nordmann afterwards found a living filaria, five lines and a half long.

A larger species of the Filaria has been noticed in the eye of the horse.

12. Filaria bronchialis.

A third species of filaria infesting the human body, was detected by Treutler in the enlarged bronchial glands of a man. It was about an inch in length, slender, and emitting the male spiculum from an incurvated obtuse anal extremity. Treutler

Filuria bronchialis, magnified.

is the only pathologist who has met with the Filaria in this situation in man; but in many animals the bronchial tubes are often loaded with worms of this specics.

13. Tricocephalus Dispar,

The

(from θριξ, τριχος, hair, and κεφαλη, head,) or Trichuris, as it was formerly called. This entozoon was only discovered towards the close of the last century. Like the Filaria, it is characterized by an orbicular mouth, but differs from it in the capillary form of the anterior part of the body, and in the form of the sheath or preputial covering of the male spiculum. Tricocephalus measures from about an inch and a half to two inches, and its capillary portion, which makes about two-thirds of the entire length of the animal, is transversely striated, and contains a simple straight intestinal canal. The thick part of the body is spirally convoluted, and plainly exhibits the intestine which is here sacculated, and terminates in an obtuse anal extremity, from which projects the spiculum and its sheath, in form like an elongated cone, and attached by its apex. The corresponding extremity in the female possesses a simple foramen, which, like the outlet of a cloaca, serves the office both of anus and vulva. The head of the worm is acute, with a small simple mouth. It is necessary to observe that many writers, and amongst others

Tricocephalus Dispar.

* Natural size.

a, Capillary anterior extremity. b, Intestinal canal. c, Preputial extremity. d, Spiculum.

Dr. Baillie and Dr. Mason Good, have fallen into the error of describing the long attenuated part of the animal as the tail.

The Tricocephalus Dispar inhabits the large intestines, and principally the cæcum; but it occurs occasionally in the small intestines. It is often found adhering by its small or anterior part to the mucous membrane, the remainder of the animal being lost in the canal. It is in consequence of this circumstance, and the minuteness of their size, that they are seldom observed in the stools. This species of worm, which infests many of the mammalia as well as man, exists sometimes in great numbers.

In the winter, at the commencement of the year 1761, the period at which this worm was first discovered in Germany, an epidemic broke out in a corps of the French army stationed at Göttingen. Roederer and Wagler, who have given us an account of this epidemic, under the name of morbus mucosus, having frequently found numbers of the Tricocephalus in the dead bodies of the soldiers who died of the disease, were induced to regard these animals as the cause of it. Now it is remarkable that M. Thibault, who has recently investigated the cholera morbus during its fearful ravages at Naples, in a communication lately made to the Royal Academy of Medicine, at Paris, states, that in the examination of more than 150 bodies of persons, all cut off within the fourth or fifth days of the disease, he found more or less capillary injection of the mucous membrane of the intestinal canal, hypertrophy of the follicles, a considerable quantity of a thick and viscid mucus, and large numbers of the Tricocephalus, together with the Ascaris lumbricoides and Vermicularis in the intestines. The unexpected discovery of this species of worm, in cases of cholera, which is due to Ramaglia, was thought at first to account for the disease; but M. Thibault and his confrères, acting with greater caution, and in a more philosophic spirit, than their German predecessors, Ræderer and Wagler, extended their researches to persons dying of other diseases than the epidemic, when it appeared that in the inspection of the bodies of eighty individuals, dead of various affections, these worms, together with the viscid mucus, enlarged follicles, and preternatural injection, were found in all of them without exception, although they were present generally in less quantity than in the bodies of cholera patients. These worms have been detected in Germany, since they were first observed, in conjunction with most forms of disease, and in neither of the epidemics alluded to can their existence be fairly regarded in any

other light than as an accidental coincidence, though they may have tended to modify and complicate the diseases, for the cause of which they were mistaken.

No symptoms characteristic of the presence of the Trico ephalus have hitherto been noticed, and they appear to reside quietly in the cæcum without exciting much uneasiness.

MALIGNANT FEVER OF BRITISH GUIANA.

To the Editor of the Medical Gazette. SIR,

THE newspapers have from time to time informed us that a fever of a very maligand important colony, British Guiana. nant character was raging in that rich As I am not aware that any account of this fever has appeared in our medical publications, and as the mortality in the colony was at one time so great as to excite considerable alarm, I think the inclosed extract of a letter, lately received from my much-valued friend, Dr. William Fraser, health-officer of siderable interest by many of your the colony, will be perused with conreaders. The facts brought forward by Dr. Fraser are, perhaps, the strongest that were ever adduced in confirmation of a certain variety of the yellow-fever being highly contagious-at least they leave no doubt on my mind that the late epidemic in Demerara was not only contagious, and propagated only by contagion or infection, (I know not which is the best term), but that it certainly was introduced into the colony in consequence of the quarantine laws having been suspended at the urgent request of the merchants of George Town (the capital), because they led to some trifling expenses; and as alleged, "that their ships were needlessly and uselessly detained, merely because they came from places where contagious or infectious diseases were prevalent, though they had not a sick man on board.” Now I believe, sir, there is no doctrine more firmly established than this-that a man may convey contagion from one person to another without in any way suffering from the disease himself, and therefore maintain that we ought never in any instance to allow the crews of ships, coming from infected places, to have free intercourse with the inhabitants of the port at which