WITH COMPLIMENTS OF THE AUTHOR. Tt is regretted that several typographical errors occur in this paper, but the reader can doubtless, correct them without being led into error. PLEASE EXCHANGE. A copy of any notice or criticism, also any information, which will enable the author to revise and make more complete a future enlarged monograph on the same subject, will be highly appreciated, and, as far as possible, reciprocated. Address T. B. Bedding, New Castle, Ind., U. S. A. TRICHINA SPIRALIS AND TRICHINOSIS, INCLUDING AN EXAMINATION OF INDIANA HOGS, ■Prepared Under the Direction of the Indiana State Board of Health, By THOMAS B. REDDING, A. M. Ph. D. Fellow of the Royal Microscopical Society, Etc. W. B. Burford, Printer. 258 STATE BOARD OF HEALTH. Newcastle, Ind., January, 1885. E. S. Elder, M. D., Secretary of Indiana State Board of Health: Dear Sir—In pursuance of the request of the State Board of Health, commu- nicated to me by you, I undertook, on the 15th of October last, the examination of five hundred Indiana hogs, with a view to determine how extensively they might be infected with trichinae, and to prepare a report upon the subject of trichina* and trichinosis. I have been able to give only evenings and odd moments to the work, being engaged in the active duties of my profession ; hence, the labor has been performed under pressure for want of time, but has been as thoroughly performed as possible within the limited time given to me. I herewith present to you my report, which embraces not only the work done since the time I entered upon this work for the State Board, but also much previous study and investigation in the same direction. I hope the work may result in good to the cause of public sanitation. With respect, I am yours, truly, T. B Redding. TRICHINA SPIRALIS AND TRICHINOSIS, INCLUDING AN EXAMINA- TION -OF INDIANA HOGS. PREPARED UNDER THE DIRECTION OF THE INDIANA STATE BOARD OF HEALTH BY THOMAS B. REDDING, A. M., PH. D., FELLOW OF THE ROYAL MICROSCOPICAL SOCIETY, ETC.. • 1884:—1885. In presenting this report, I have the pleasure of acknowledging my indebted- ness, for many of the facts and thoughts contained therein, to the valuable and exhaustive report of the late W. C. W. Glazier, M. D., Assistant Surgeon, Marine Hospital Service, On “ Trichnse and Trichinosis.”—1881, prepared under the direc- tion of the United States Marine Hospital Service ; and also the excellent work of M. Joannes Chatin, entitled “ La Trichine et la Trichinose,”—1883, J. B. Bailliere et Fils, Paris; Also to the works of Leuckart, Cobbold, Pagenstecher, Gerlach and others. I also tender thanks to Messrs. Kingan & Co., of Indianapolis; Messrs. Baldwin & Roberts, of Newcastle, and Messrs. Collins and Welch, of the same place, for favors shown in furnishing specimens of pork; also to Dr. E. S. Elder, and others, for use of valuable books. INPORTANCE OF SUBJECT—INTRODUCTION. “ My people are destroyed for lack of knowledge.”—[Hosea iv, 6. “Therefore shall the land mourn and every one that dwelleth therein shall languish with the beasts of the field, and with the fowls of Heaven; yea, even the fishes of the sea shall be taken away.”—[Hosea iv, 2. TRICHINA SPIRALIS AND TRICHINOSIS. 259 These prophetic words of Hosea, though spoken of a different subject, are as true to-day, when applied to the lack of the peoples’ knowledge of sanitary laws, as when uttered by Hosea more than two thousand five hundred years ago. The cat- tle are dying of anthrax, tuberculosis, Texas fever and other preventable diseases; hogs are dying of cholera and trichinae; sheep are infected with strongylus and numerous parasites, that proper knowledge, rightly applied, would prevent; our chickens and turkeys are dying of cholera and other diseases; even the fish of our rivers and seas are being poisoned by the filth poured into them by men, while men are dying of small-pox, malaria, cholera, trichinosis and many other preventable diseases; and the children are being slaughtered by the millions, while they ought to live to be old men and women, so that it might be said of our land: “There shall yet old men and old women dwell in Jerusalem, and every man with his stafFin his hand for very age, and the streets of the city shall be full of boys and girls playing in the streets thereof.”—[Zecli. viii, 4, 5. That the people are destroyed for lack of knowledge is alarmingly true. Many thousand perish every year for the want of knowledge within easy reach, yet the mass of humanity lives on in willing ignorance, without an effort to know how to live well and long. A large per cent, of diseases come to man through the use of poisonous, diseased and parasite-infected foods, and from poisonous, disease-infected water and drinks. It is part of the work of sanitarians and Boards of Health to awaken people out of this sleep of death; to stimulate them to know themselves and their food ; to choose the good and reject the bad. One of the most distressing and fatal diseases, resulting from the use of un- healthy food, is trichinosis, infection with a disease that can be infallibly guarded against, if we have the knowledge to do so, and fortunately that knowl- edge is easily obtained. This disease has swept its thousands into the grave pre- maturely through intense agony and suffering, all for the lack of knowledge and inspection. There need never be another case of trichinosis, if the world will only look and see, or know and do. The rejection of all trichina-infeeted meats, or their thorough cooking will absolutely protect from and prevent trichinosis; but the thorough cooking, while it will kill the parasite, will not render the food as healthy as it should be for human use. The attitude of Germany, France, Italy, and other foreign nations toward the American hog, and their refusal to give him a passport to their markets and the stomachs of their people, has touched our American people in a very tender place— the pocketbook—and far more interest has been awakened in the subject of trichinae by this unfavorable action of foreign governments than from interests of health or sanitation. It has been repeatedly charged by many foreign scientists and investigators, that American hogs are more generally infected with trichina} than those of any other country. Our American investigators and scientists are not able to confirm or deny this charge for lack of sufficient observation. Very few examinations have been made in this country, and before this question can be settled there must be systematic inspection, embracing our entire country and a large number of hogs. Not only do the interests of health and the preservation of human life demand this, but the vast commercial interests involved in our pork raising makes it less, but forcibly imperative. Not far from forty million, hogs are annually produced in our country, of which about three and a quarter millions are produced in Indiana. If these forty million hogs average two hundred pounds each, we shall have a total of eight thousand STATE BOA It D OF HEALTH. million pounds. If 2 per cent, of these, probably a very low estimate, be infected with trichina*, we shall have one hundred and sixty million pounds of infected pork, every pound of which is capable of producing death in the consumer. If it be true that our meats are thus infected, we have no right to complain of our uninspected pork being excluded from foreign markets. It will be wiser, far more humane, and honorable, to provide that poison meats shall neither be shipped to foreign ports, nor sold to our own citizens in our home markets; that every hog shall be inspected before going upon the market. The extreme limit of cost for a thorough inspection for trichinae need not, in any case, exceed the one-tenth of one cent per pound, or twenty cents per hog, and can probably be done for less than one-fourth of this sum—a very small expense compared with the safety secured at home and the advantage of the freedom of foreign markets. But the advantage of proper inspection, investigation and oversight, in this di- rection, will not only conduce to the health and safety of our own people, and open to us the markets of the world, but will increase largely the demand for American inspected meats, and, at the same time, will enable and stimulate our farmers and all persons interested in pork raising, to so feed, manage and handle their hogs as to reduce the infection to its lowest limit and, probably, ultimately to entirely stamp it out of existence among us. In order to present the subject of trichina and trichinosis so as to lead to a ful comprehension of its importance in every relation, I shall give, not only the results of my examinations of Indiana hogs for trichinae, under direction of the State Board of Health, but, also, a brief history of the discovery of the parasite; its natural history; a description of the proce ses of infection of men and animals; symptoms of the disease called trichinosis; methods of prevention; statistics of epidemics, and of examinations; methods of inspection and study, and a list of the principal authorities upon the subject. EXAMINATION OF INDIANA HOGS. About ten years ago my attention was directed to the necessity for the examin- ation of all pork used as food. Since that time I have not allowed any pork to be used in my own family that was not first submitted to microscopical examination for trichina spiralis. During that time, and up to October 15, 1884, I examined in all, probably as many as two hundred different animals, but of most of these exam- inations I kept no record. In this report I shall only include such examinations as I made records of at the time. Since October 15, 1884, I have examined the flesh of five hundred and fifty hogs. I shall not give details of the several examinations made, further than is nec- essary to present the results, but can furnish them, if desired, at any time. “In 1881 I examined twenty hogs and found trichinae in two, one of them ex- ceedingly full; in 1882 1 examined twenty-five and found but one that contained any of the parasites. Last year I examined, at various times during the year, fifteen, and found one that contained trichinae; these were hogs that had been killed and were sold on our market. I also, during the past winter, examined the mus- cles of three hogs that had died and were left on the street a few days, and found trichinae in each of them in great abundance; they were fed in very dirty pens and where rats greatly abounded.” (216 p. 45.) In nearly all cases I examined five sections from each hog. The sections w ould average nearly three-quarters of an inch square, and from the 1-100 of an inch to 1-150 of an inch in thickness. Many times I examined more than five sections to the hog. The methods of examination are given elsewhere more fully. TRICHINA SPIRALIS AND TRICHINOSIS. 261 From October 15, 1884, to December 31, 1884, I examined the flesh of fifty-two hogs, received from the meat market of , at . They kill, mostly, young hogs, ranging from nine to eighteen months old. The first twenty-four examined were free from trichinae. The twenty-fifth, a hog about eighteen months old, raised on a farm about two miles from town, contained numerous encysted trichina*. The thirty-ninth, forty-sixth, forty-seventh, forty-eighth, forty-ninth, fiftieth, fifty-first and fifty-second hogs examined, contained trichinae. The others were free. The fiftieth and fifty-first not only contained recently encysted, but numer- ous non-encysted and embryonic trichinae; some just entering the muscle fibers; others yet in the connective tissue. Numbers forty-six to fifty-one inclusive, had been fed a few weeks in the lot adjoining the slaughter house, and had been fed, partly, upon the offal of slaughtered animals and probably were infected from that source. They were all recent cases. Number fifty-two contained an immense num- ber of trichinae in the abdominal muscles, and a moderate number in the muscles of the back. The butchers assured me that numbers forty-six, forty-seven and forty-eight would be free from parasites, as they had raised them themselves. Upon learning from them that they had been fed as above, I was quite sure that I would find them infected, and the microscopical examination abundantly corrobo- rated my suspicions. They were much surprised when I told them the result and explained to them the probable source of infection, and assured me that they would not thereafter feed hogs upon the offal of butchered hogs. On the 25th of Octobar, 1884, I received from Messrs. Kingan & Co., of Indi- anapolis, specimens of 300 hogs, taken from the psoas muscle, or tenderloin. The first 175 specimens examined contained no trichinae. The 176th, 218th, 219th, 226th, 230th, 233d, 242d, and the 267th specimens contained encysted trichinae. Most of these contained from one to five trichinae to each five sections examined. Nos. 218, 230 and 242 were very full of encysted trichinae. No. 130 showed some cysts partly calcified. The other specimens examined were not infected. Total examined, H00; infected, 8, or 2f per cent. I was not able to learn any particulars as to the age or methods of feeding this lot of hogs. I have examined specimens from 176 hogs received from the pork house of Messrs. Baldwin & Roberts, the second largest establishment in the State. In the first twenty-six I found no trichinae. In the twenty-seventh I found enormous quantities of encysted trichinae. This specimen contained probably 12,000 to 20,000 parasites to the cubic inch of muscle. A small section about half an inch square and about 1-150 of an inch in thickness, contained thirty encysted trichinae. Among others examined I found one with encysted and embryonic trichinae, and six recently infected cases containing in the intrafascicular tissues large num- bers of embryonic trichinae. Two of them were extremely full of these embryos. In most of the specimens muscular degeneration had commenced, and many of the embryos had entered the fasciculi, and the first, or preparatory, processes of encyst- ment had commenced. It is probable that these recently infected hogs had been kept a few days in the yards where large numbers of other hogs had been kept, and were infected from this source; but as I could not trace their history, I can only speculate upon the source of infection. I examined, during the year, twenty-two hogs from other sources, one of them containing encysted trichinae. Total examined, 550; infected, 25; equal to a fraction over 4£ per cent. The highest percentage of infected hogs were those of the retail butcher shops, in which, out of fifty-two animals examined, nine, equal to about per cent. 262 STATE BOARD OF HEALTH. were infected. In this case the animals intended for sale were kept from a few days to several weeks about the slaughter house, and fed upon animal refuse and offal from slaughtered animals. No doubt this was the source of infection in most of the cases. How many more retail butchers throughout the State manage in the same way? I have no hesitancy in predicting that in all such cases a large per- centage of the hogs killed will contain trichime. METHODS, INSTRUMENTS, ETC. I have used in my investigations Beck's microscope stand, No. 44, with mechan- ical stage, achromatic substage condenser ; Beck’s 1, §- and 5-inch objectives; Beck’s oculars, A, B, C and D; Tolle’s first quality duplex four system immersion, objective of 180° angular aperture; Tolle’s 4- and J-inch oculars and amplifier; Gundlach’s objective of 110°. When examining merely to determine the presence of trichinae, I used a f inch, objective and 2-inch eye-piece, giving about 75 diameters, or the 1-inch objective, with same eye-piece, giving about 60 diameters. These are as high powers as should be used for the detection of the presence of the parasite. The higher powers were only used in the study of the structure, histology, and other facts relating to the life-history of the trichina, and the formation of its cyst, etc. Having ascertained, in certain cases, that I had a specimen of a very recent invasion by the parasites, in their embryonic state, I resorted to the higher powers, ranging from 250 to 2,000 diameters, for their more complete study and investigation. I also used like pow- ers in my studies of the intestinal trichinae, their ovules, and the development of the ovules prior to their birth. The apparatus and lenses used were all first-class, and every reasonable precau- tion was taken to prevent any errors of observation. My work has been done slowly and cautiously, from the first, and 1 trust my observations have been cor- rect. Had more time, however, been allotted to the work than has been possible since I was requested to undertaker it, I think my report could have been made more valuable by including much that is necessarily left out. The flesh for examination was generally taken from the psoas muscle, or tender- loin, and from the pillars of the diaphragm. Other parts have occasionally been used. The sections have sometimes been prepared by freezing the muscle and then cutting in the microtome; at others by using a Valentine knife, but most frequently by taking a thin, ribbon-like piece of the muscle running parallel with the fiber, and placing this in the “ Bauscli and Lomb” compressor, No. 1,009, and by its use spreading and thinning the muscle for examination. This compressor is admirably suited to this work, and enables one to prepare specimens for examination quite rapidly. Sometimes it may be an advantage to moisten the specimen with a small drop of a solution of one part of liquor pottassse to seven or eight parts of water, or a solution of glacial acetic acid, one part to six of water. These make the specimen more transparent and facilitate the spreading and thinning of the tissues, but I seldom find it necessary to use anything of the kind. I have often used the various staining reagents, but they are not necessary except to facilitate the histo- logical study of the parasite and its cyst. If the specimen has been in salt, or other hardening reagent, the section should be allowed to soak in pure fresh water a short time before examination, and then treated with a drop of the potassic or acetic acid solution. The use of a mechanical stage and achromatic substage con- denser facilitates the examination of every part of the tissue with the most favor- able conditions as to light, the condenser enabling us to readily modify the light to 263 TRICHINA SPIRALIS AND TRICHINOSIS. suit all the conditions of the tissue. In order that an inspection may be accurate and exhaustive, revealing all that is to be seen, the lenses used should be of the best quality, the light should be under perfect control, the sections should be taken parallel with the libers of the muscle, and should be thin enough to allow perfect illumination—say from to of an inch in thickness—and be mounted upon a suitable compressor or upon a glass slip with suitable glass cover. If the tissue to be examined is dry, or not fresh, the sections should be moistened with one of the solutions named above, or with water and glycerine, equal parts. To obtain intestinal sexually perfect trie hinge, their eggs and embryos, I fed cats, rats and mice trichinized flesh, and killed them at different intervals, com- mencing twenty-four hours after ingestion and extending to twenty days, and in one case six weeks. In this way the parasites were obtained in all stages of devel- opment. In this report I have had time only to give general results, and can not give details of the several examinations. It should be understood that all these tedious processes of investigation are not necessary merely to detect trichina in the flesh of the hog, but are necessary to one who desires to know the life-history of the parasite, the method of encystment, the histological and pathological changes that take place, and the effects upon the animal. REFERENCES AND BIBLIOGRAPHY. The references to authorities in the following pages are by numbers, referring to the authors named in the bibliography. Thus, (46) refers to bibliography “ 46, Colbold on the Discovery of Trichina, etc., Lancet, 1866.” The bibliography at the close of this article is as perfect as I have been able to make it from the material at hand and in the time at my command. No biblio- graphy has heretofore been given by any American writer upon this subject, and I trust this will serve a useful purpose to American students. Titles of works are given without translation, as is best, and saves confusion and mistake in ordering books. PSEUDO-1 RICHIN.F.. It is not every parasite, found in the flesh of animals, that is a trichina spiralis. Investigators have described nine species of the trichina, some of them, probably, incorrectly classed as such. The species and names of the investigators who named them are given below, to-wit.: Trichina spiralis: Owen. (200.)*' Trichina atfinis: Diesing. (68 A, t II, p. 114.) Trichina cyprinorum: Diesing. (Same, p. 115,) also (70, p. 60-61.) Trichina cystica: Salisbury. (235, t IV, 1868, p. 376.) Trichina inflexa: Dujardin. (70, p. 294.) Trichina Microscopica : Polonio. (214, A.); see also, (176 daz. Med. 4 June, 1881. Trichina agilissima: Molin. (189 A, p. 16.) Trichina circumflexa: Polonio. (214 A.) Trichina anguilla;: Bowmaun. (169 A.) See also, (68 A, t 2, p. 115.) For the distinguishing differences between these nine so-called species of trichina, I would respectfully refer the reader to “La Trichine et Trichinose Par Joannes Chatin,” 1833, Paris, (39)* and the authorities above referred to. ""Refers to numbers in Bibliography, which see. 264 STATE EOARD OF HEALTH. There can be little danger of any one being led astray who has studied the trichina spiralis as it usually appears in the hog, especially in its encysted state. But there are other objects, that may be called pseudo-trichina, that may lead the non-expert into error. One of the most common of these, which is very often found in the hog, is the pxoro-spermice, sometimes called “ Rainey’s sacs.” A little attention, however, will avoid any mistake. Psorosperms are granular, elongated bodies lying within the sheath of the muscle fiber. The fiber, in the case of the psorosperm, retains its transverse striation, not only on either side of the enclosed body, but extending directly from the extremities, while the trichina entirely destroys the striation, especially at the extremities. Inexperienced observers might, also, possibly mistake the strongylus paradoxus, and the str. filaria, for trichina?. The first is found in the air passages and lungs of some animals, and the second is found in the sheep of Texas, and elsewhere. Other parasites that have, possibly, sometimes, been mistaken for trichinae are the following: Spiroptera strumosa, spiroptera erinacei, spiroptera obtusa of the rat and mouse, physaloptera clausa of the hedgehog, the ascaris of the mole, the spiroptera of insects, the filaria san- guinis, the anguilula or vinegar eel, tricocephalus dispar, cysticerci, and probably a few other similar organisms. But it is only the inexperienced observer that will be likely to be misled by any of these. Space will not allow me to describe the distinguishing characteristics of these several parasites, etc. Some of them will be found illustrated in Dr. Glazier’s report. (111). See, also, Chatin, (39). The principal danger of mistakes will be in cases of fresh invasions, where the trichina? is still in its embryonic state. While in this stage it is not capable of producing trichinosis in any other animal through eating of the muscle tissues. But where hogs feed with others, or eat of the viscera of dead animals, or the ex- crement of other animals containing living females and embryos, they may, by so doing, receive into the stomach the newly born embryo, or the female contain- ing young, and, possibly, thus become infected. In 1821-2 Tiedemann (269) described calcareous concretions found in the body of an intemperate person, who had suffered severe and frequent attacks of what had been taken for gout. These concretions are supposed, by some, to have been calcified trichinae cysts, but the description show them to have been of different sizes from trichinae cysts. In 1828 indications were noticed in the human muscle by Peacock, and in 1829 by Klencke, which may possibly have been caused by trichinae, but scarcely merits notice as a discovery. (39.) The history of the discovery of this parasite may be divided into two periods: the first from 1832 to 1835, and the second from 1858 to 1860; the first English, the second German. The first described the parasite in its larval, or encysted condition ; the second disclosed its life history. (39.) In 1832 Dr. Hilton (122) described certain gritty particles found by him in the body of an old man who had died of a cancerous affection, which he attributed to parasitic origin, possibly cysticerci, but the proof that trichinae were present is not conclusive. In 1834 Sir James Paget (208), then in St. Bartholomew’s Hospital, first ob- served the trichina coiled up in its cyst. He submitted it to a rigid microscopical examination, and described the same as he found it. Dr. Wormald, in the same hospital with Paget, the following year submitted to Dr. Richard Owen specimens TRICHINA SPIRALIS—HISTORY OF DISCOVERY. 265 TRICHINA SPIRALIS AND TRICHINOSIS. of the same flesh examined by Paget, with a description of Paget’s discoveries and diagnosis. Dr. Owen (200) fully confirmed the diagnosis and fixed definitely the taxonomic place of the parasite and gave it the name “ trichina spiralis,” a name now almost universally recognized in all languages where it has been described. The name is from the Greek word thrix ( Ta hair, and the specific name, spiralis, because coiled up in its cyst in a spiral. • Owen’s and Paget’s descriptions were, however, very incomplete and gave rise to a good deal of discussion as to the palace this parasite should occupy in natural history, as well as concerning its •structure. (On this subject consult 163, 128, 80, 243, 46, 64, 18, 173, 278.) For nearly twenty years the history of the trichina spiralis remained almost stationary. In 1835 Farre (80) described the intestinal tube and its three divisions, and recogpized the ovaries. Bischofi confirmed these discoveries, and Luschka dis- covered that the slender end was the head. Bristowe & Rainey, Kiichenmeister and others, made still further discoveries in its life history, and in 1859 Virchow described the sexually mature worms. Leuckart somewhat advanced our knowl- edge of the subject during the same year, and efforts were put forth in various directions, by experiment and observation, to fully make out the life history of the parasite. In 1860 Dr. Zenker treated a case of supposed typhoid fever, a girl aged about nineteen, who had been sick about twenty days. She complained of great fatigue, loss of appetite and intense thirst; there was some fever, swelling, abdominal pains, and most of the usual symptoms of typhoid fever, for which the case was treamd, but there were also pains, limited at first to certain mu-cles, then becoming general and incessant, persisting day and night, then followed violent and painful contractions of the limbs resisting every effort at extension. The girl entered the hospital on the 12th of January and died on the 27th of the same month. The anomalous symptoms had been carefully noted by Dr. Zenker. An autopsy was held, and a careful and minute microscopical examination made of her voluntary muscles, which were found filled with encysted trichinae. The autopsy showed that certain lesions, peculiar to typhoid fever, such as alterations of Peyer’s glands, were lacking, and a microscopical examination of the intestinal contents showed “ numerous nematodes reproducing the taxonomic character of trichina spiralis, but having attained their complete development.” (39.) Dr. Zenker, stimulated by his discoveries, made a rigid examination of all the circumstances and conditions under which these parasites had entered the organism and quite thoroughly reviewed the etiology of trichinosis. His discoveries were extensively published and stimulated research. He called the disease triehinen- krankheit, or trichina sickness. (300, 39.) He visited the girl’s parents and obtained from them the facts relating to the origin of her disease; learned that she had eaten of pork at a certain time, bought at a certain shop; he visited the butcher who had supplied the meat, and found that he had a charge for pork sold the father at the date named, and that the butcher had himself eaten of the meat, and had been made very sick, but that he had thrown it up; he also learned that a number of other persons had been made sick by eating of the same pork. The butcher came to th<> conclusion that the meat was not healthy, and refused to sell any more of it, and had laid away the portion remaining unsold. Dr. Zenker obtained some of this pork from the butcher. He examined it under the microscope and found it filled with trichina-. These discoveries furnished the means for unraveling the mystery. The girl had eaten of the trichinized meat; the cysts were dissolved in the stomach ; 266 STATE BOARD OF HEALTH. the larvel trichinae were set free and developed sexually; the females gave birth to a numerous progeny; these embryos, finding their ways into the muscles, gave rise to the final symptoms, as observed by Zenker. These discoveries determined him to make a series of experiments. He fed Ihe infected meat which he had obtained of the butcher to various animals, and in them reproduced all the characteristic symptoms of his trichinenkrankheit, or trichinosis. By these experiments the developmental cycle of the trichina, its mode of pro- pagation and dissemmination, the etiology and prophylaxis of trichinosis were elucidated in a most complete and brilliant manner. (39.) Cobbold, (52 p. 152) in speaking of Dr. Zenker’s experiments and discoveries, says: “Never in the history of biological science have more valuable issues fol- lowed the method of experiment upon animals. Not only has human life been thus saved, but animal life also. State medicine and sanitation have received an immense impulse. The good that has already resulted is incalculable.” Trichina spiralis was first found in the hog by Prof. Leidy, of Philadelphia, in 1846. (160 p. 107 and 159 p. 353.) Space will not permit me to further trace the history of discovery. MALE AND FEMALE TRICHINA. The trichina as found in the cyst is not complete in its development. It is a larval form of the perfect worm. Before it can become perfect it must be freed from its cyst by entering the stomach of some animal suitable to its developments While the trichina remains in the cyst it does not multiply, nor grow, nor change its position. If a piece of trichinous flesh be eaten by man, or any animal in which it may find suitable environments for development, the gastric and other fluids of the stomach, within two to five hours, dissolve the walls of the cyst en- closing the parasite, which is thus set free within the stomach. When thus freed, it rapidly developes into its mature and perfect state. After becoming free, the trichinae pass into the small intestines. Then commences the rapid increase in size of the worm by the development of the seuxal organs, and thus the increase of its length is limited principally to its posterior portion, while the anterior increases in diameter only, and in twenty-four hours, after feeding, they may have increased one-half their former size, and are, for the most part, capable of procreation.” Some of the capsules may remain undissolved in the stomach two or three days. Most of the trichinae will, however, be found sexually mature within three days. The full-grown male trichina is from to of an inch in length and about jjfu of an inch in diameter; the full-grown female is from | to of an inch in length and about of an inch in diameter. The posterior part of the female continues to enlarge after sexual maturity for some time, to make room for the large number of eggs produced. Copulation takes place within about fifty to sixty hours after the worms are set free, and within fifty-four to ninety hours, most, if not all of the females are preg- nant, and within five days the embryos begin to be born. These processes may con- tinue for two weeks or more. (Consult Pagenstecher, Delpeche, Cobbold, Leuckart and J. Chatin.) The outer cuticle of the trichina consists of a delicate, thin, transparent, struc- tureless, annulated, chitinous membrane, about xsirnr °f an inch in thickness. The rings are more easily seen in the muscle trichina coiled up in its cyst than in the TRICHINA SPIRALIS AND TRICHINOSIS. 267 mature worm. Just beneath the outer covering is a striped longitudinal layer of muscular tissue. On the inner side of this layer, closely pressed together, is a strata of finely nucleated cells, which constitute the lining of the abdominal cavity. The mouth is terminal. The body is curved in one direction, and, “ if we recognize the female genital opening as being on the ventral surface, the curve is uniformly towards the dorsal side.” The terminal hooks of the male are found on the convex or ventral side, attached on either side of the anus by broad round bases. The internal organs consist of an intestinal canal, organs of reproduction and a brain. The canal is very closely alike in both sexes. It is divided into three parts: The first in the anterior part of the body; the second, less constricted, in the central part of the body, or rather forward of the central part; and the third part, which occupies the posterior third and part of the middle third of the body. The stomach composes the anterior part of this last portion. The brain is a small mass of round ganglion, nucleated cells, surrounding the oesophagus, and from this brain a few very fine nerve fibers may be traced a short distance. The sexual organs of the male are developed while in the larval state, but the contents are not matured till his liberation. The hooks are also partly, if not wholly, developed after his liberation from the cyst. In the female the reproduc- tive organs are but partly or imperfectly formed in the-larval state, but fully mature within two or three days after being set free. The female reproductive organs consist of an ovary, a uterus and vagina, all lying in an almost direct line, and the uterus, in the fully matured specimen, merging gradually into the vagina. The eggs, or ovules, are produced along the whole length of the ovary on one side, appearing in the earlier stages closely pressed together like a narrow band of minute cells. As they increase in size they become detached and move to the center and opposite side of the ovary. The ovules are spherical, have a germinal vessicle with a comparatively large neucleus, surrounded by a clear vitellus and an exceedingly thin limiting membrane. (39). The seminal elements, after copulation, occupy such a position in the uterus, that the ovules, in passing out of the ovary into the uterus, must pass through the sperm, by which they are then impregnated. When thus vitalized, the ovules gradually pass downwards towards the vagina, developing as they progress. When near the beginning of the vagina the young trichina has so far developed within the ovule as to be ready for liberty and bursts the delicate wall or membrane con- fining it and escapes as a bent or curved embryo. As the embryos advance toward freedom, they straighten out and lie, one behind another, in single file, and passing out through the vagina, are born, one by one. The birth of these embryos usually takes place within five days after copulation, or within six to eight days after the infection and liberation of the larval trichina- within the stomach. But as all of the ovules do not mature and become impregnated at the same time, the embryos continue to be born, sometimes for one or two weeks, or even longer. The female developes a very large number of eggs. Often 400 to 600 impreg- nated eggs and embryos may be found in the uterus at a time. This may continue for weeks after the birth of the young commences. On this account it is not very difficult to observe the successive stages of ovule development. It has been claimed that ova have been seen attached to the wall of the ovary eight weeks after infec- tion. It is estimated that one female will give birth to two thousand, or more, young trichinae. The embryos are born one to three each hour. The processes of development of the egg of the trichina are very beautifully illustrated in plate two, figures 6 to 22, and the further development of the embryo 268 STATE BOARD OF HEALTH. in plate three, figures 23 to 33, of “ La Trichine et Trichinose, par Joannes Chatin,” Paris, 1883. (39.) I should be glad to reproduce these exquisite plates here, if it could be done, but must refer those who wish to study this subject to the above work. The entire development of the ovule occupies about three days. The female commences giving birth to her young possibly as early as the fourth day, in some cases, and may continue until the twelfth week, but usually not so long. Did cir- cumstances permit I should be glad to more fully describe the histological elements, the anatomy and reproduction of the trichina. The embryo, before birth, in its developed condition, is about °f an inch in length and about half as much in diameter. While in the body of the mother it has the appearance of a delicate granular thread, but afterwards becomes more transparent. At this period the extremities are so much alike that it is difficult, if not impossible, to determine which is the head; but this stage soon passes away. Sometimes in the oldest embryos a delicate cuticula and an axial beaded line can be distinguished. (Pagenstecher.) In the intestine embryos have been found of nearly all sizes, from xoVo an inch to of an inch, and with a diameter reaching -gihsjs of an inch. “The size and appearance of those embryos that migrate to the muscles, remain un- changed during migration. The first changes in the migrating worms are observed after they have reached the fasciculi and take on a condition of rest. (Leuckart.) From the intestines most of the embryos soon migrate to other parts of the body. They are first found in the abdominal and pleural cavities and pericardium, and so constant is their appearance in these cavities that tl ese “may be considered their normal stations.” (Leuckart.) They are generally most abundant in the abdominal cavity. From these places they speedily migrate, probably in part through the openings which serve for the passage of the oesophagus and the large blood vessels, and partly through the walls of adjacent parts, and possibly through the blood—though this is doubtful—to the surrounding connective tissue, and thence into the muscles of the various parts of the body. They may often be found free in the loose connective tissue of various parts. Following this loose connective tissue that binds together muscles and other tissues, they find ready access to the remotest parts of the body within a few days after the migration commences. The duration of the migratory period has not been definitely determined, but probably does not continue more than eight to ten days. (103, p. 13. 168, p. 568.) Sometimes the embryo may be found in the muscle fiber before any apparent change has taken place in the fibre, which indicates a very recent arrival, for de- generation commences in the muscle fiber almost immediately upon the embryo entering the fiber or its sheath. On the 28th of November, 1884, I examined a specimen from the pillars of the diaphragm of a hog which had been fed, a few days previous to killing, upon offal from the slaughter-house. I found in the loose connective tissue great num- bers of free embryonic trichinae, and also numerous changed muscle fasciculi into which they had penetrated. More than 100 free embryos, and 25 encysting em- bryos, were found in a section about £ of an inch square and of an inch in thickness. The section embraced the loose connective tissue between two adjacent bundles of muscles. I examined these with powers ranging from 75 to 1,000 diameters. It is only with careful manipulation and good lenses that the embryo can be identified when it has so recently entered the fasciculi. I have found free and non-encysted embryos in large numbers in more than a dozen different hogs. When the embryo enters the muscle fiber and becomes encysted therein, or, TRICHINA SPIRALIS AND TRICHINOSIS. 269 rather, when it commences that process, it “destroys the inner part of the fascicu- lus, not only in its immediate vicinity (Leuckart) but, sometimes, to the extent of a quarter of an inch in length.” “This destruction consists of a morphological metamorphosis; * * * the fibrillar substance degenerates to a fine granular detritus, and all that can then be distinguished are the neuclei, which appear as small oval bladder-like bodies from xxVo 1° TffVs °f an inch long and °f an inch in diameter, with a sharply defined wall, and with sometimes single and sometimes double solid neucleoles.” (Leuckart.) Neuclei are always more numerous in degenerating than in normal muscle fasciculi. This degeneration renders the fibrilla more or less opaque, and “ it ap- pears as a dark thread-like stripe.” It also loses its elasticity or contractility, and, owing to this condition, will often be found projecting a short distance beyond the cut ends of the sections. . Various theories have been advanced to account for this degeneration of the muscle tissue. Some consider it due to the progress of the parasite through the tissues; others, that the parasite consumes the substance of the tissue; but as it receives its food in a liquid form only, by endosmosis, probably, this can hardly be true. Probably the regressive changes are due to irritation and inflammatory processes caused by the presence of the parasite. At the same time this degenera- tion is progressing there occurs a growth of small cells in the neighboring connective tissue, extending the whole length of the sheath and often beyond to other fasci- culi. Changes also take place in adjacent capillary vessels to the extent of inter- fering with the distribution of the inflammatory products. (Colberg.) (53.) When the embryo reaches the muscle fiber it enters upon a state of compara- tive, if not complete repose, and rapidly grows to its normal size as a muscle trichina. After entering the muscle a vibratory or exploring motion of the anter- ior extremity has been observed, by a few observers, for a short period of time, but I have never been able to see any such motion. In twelve to fourteen days after entering the muscle the embryo attains its full size and becomes a larval, or muscle trichina. As the worm grows it exhibits differentiations of its internal organs. As it in- creases in length it becomes more slender anteriorly, and begins to coil into a spiral, often commencing thus to coil when not more than of an inch in length. The outward pressure of the worm causes the muscle sheath to enlarge around it, and owing to the elasticity of the sheath, the cavity assumes a spindle shape. In two to three weeks, or less, the worm ceases to grow, and a bright halo will be seen surrounding it, which is now sharply limited by the enclosing muscle, and is the optical expression of the enlargement. (Leuckart, as quoted by Glazier.) In the fifth week may be seen the first traces of the cyst proper. And after about seventeen weeks the cyst has a clearly defined outline and is fully formed. It is sometimes fully formed earlier than this, possibly; in some cases as early as the sixth week. In progress of time the capsules become rounder and shorter with more or less fat globules, first at one end, and afterwards at the other. After eighteen months, and in some cases as early as the thirteenth month, calcification, the deposit of lime and mineral matter, commences to take place. In some animals, the rabbit for example, calcification has been known to commence as early as the eightieth day (206, p. 96), and several observers claim to have seen calcification in the hog within three to nine months after infection. (163, p. 67; 206, p. 9.) Leuckart (163, p. 67) substantially describes the process of calcification as fol- lows: There is, at either pole of the capsule, first a collection of minute calcareous 270 STATE BOARD OF HEALTH. granulations, at first assuming a spread-out, or flask shape. After sometime these particles become a homogeneous mass, having the form of a disk and lying between the layers of the capsular wall. Sometimes this takes place at one pole only. It is readily distinguished from the other elements of the cyst by its difference of re- fracting power. After several years the cyst may become quite opaque from these deposits. The polariscope will aid us in determining the presence of these mineral deposits. After calcification has taken place, the cysts can be seen with the unaided eye, in a thin microscopical section held up between the eye and the light, as minute white specks. I have a specimen of human muscle in which they may thus be recognized. By mascerating such a specimen in dilute hydrochloric acid the min- eral salts are dissolved, and the cysf, with the contained worm, rendered transpa- rent. As a general rule the cysts in the hog are not found calcified, owing to the fact that hogs are killed while young before that process commences. Among the six hundred or more animals that I have examined, I have found two only that con- tained calcified cysts. IN WHAT ANIMALS FOUND. Trichinae have been found in quite a number of different animals, mostly mam- mals Without citing authorities, I enumerate the following animals in which they have certainly been discovered, viz.: The hog, cat, dog, rats, mice, rabbits, hippopotamus, and in man. Also in young horses and cattle, when artificially in- fected. They are reported to have been found in the ape, the crow, the badger, marmot, marten, mole, polecat, raccoon, geese, trito cristatus, hedge-hogs, sala- manders, eels, sheep, the hen, fish, and frogs. Doubtless some of these last are cases in which other parasites have been mistaken for trichinae. It is probable that trichinae never become encysted in the flesh of birds, and are never found in the batrachians and reptilia under normal conditions. The best authorities agree that trichinae do not become encysted in birds, but in- testinal trichina, male and female, and their embryos, are readily obtained from the intestines of birds, including our domestic poultry, after feeding them trichin- ous flesh, but for some reason, not yet understood, they do not migrate to the mus- cles and become encysted, as they do in men, hogs, and some other animals. M. Chatin is of the opinion that reptiles and batrachians do not become trichin- ized, because of the temperature of their bodies not being suitable to the develop- ment of the parasite, and that their immunity depends solely upon the variable temperature of their bodies, and says that when the temperature is maintained artificially at 30° (Cent.), we may have not only perfectly developed sexual trichinae, but also the larva migrating into the intrafascicular tissues, but as soon as we aban- don the subject to the surrounding temperature, it ceases to offer the conditions necessary to these parasites. (39, pp. 82 and 85.) If these views be correct, it is sufficient to account for the occasional appearance of the trichinae, temporarily(?), in these animals. I found in the pectoral muscles of a frog, taken from a branch into which the washings, etc., from a large pork-house flow, a large number of encysted parasites, coiled in a spiral, and very closely resembling the trichina spiralis. The cysts were, however, nearly circular and quite different from those found in the hog. At the time I supposed them to be trichina spiralis, with modified cysts, and in my paper before the Sanitary Convention at Anderson, Ind., April, 1884, (216), stated that I had found trichina in the frog; but upon a more thorough examination of TRICHINA SPIRALIS AND TRICHINOSIS. 271 the parasite thus found, I am satisfied that it is not a trichina spiralis, but a dif- ferent species, which I am not prepared to name at this time. I had injected the frog with a view to studying certain parts of the viscera. Observing a thin section of the pectoral muscle to present a peculiar appearance, I mounted and examined it as a matter of curiosity. The remainder of the body had in the meantime been thrown away, before the discovery of the parasites; hence it has been impossible to verify all the points that should be verified to make a clear case. The frog was caught in the warm weather of July, and was kept in a pail of water three or four weeks, at a temperature of summer heat. This may have had something to do with the development of the parasites and the incomplete and imperfect cysts inclosing it. Cats are very frequently infected with trichinae. “Two years ago a cat, living at my barn, had five kittens. When the kittens were about eight weeks old, the mother sickened and died; about the same time the kittens also became sick, and one after another died. I examined pieces of the muscles of the mother and each of the kittens, as they died, and in all I found vast multitudes of encysted and en- cysting trichinae, and great numbers of free trichina1 in the stomach and intestines. A short time before the mother-cat sickened, I found her and her kittens making a meal off a large rat which she had killed, and which was probably the source of infection.” (216.) Two out of six other cats examined by me contained trichinae. “Herbert found trichinae in the cat in 1845, and Guelt in 1849.” (111.) Dr. Seiler, of Philadel- phia, told me a few years ago that he had seldom or never examined a cat at Phila- delplia that did not contain trichinae. In Dearborn and Ohio counties, Indiana, three out of four cats examined were full of trichinae. Voget, Rupprect, Kuhn, and numerous other authorities, report having found trichinae in cats. (286 B., p. 409, note; 112 B., p. 114; 163; 151 A.) [See Addenda.] PARTS OF BODY INFECTED. The encysted trichinae are always found in the voluntary muscles, and not often elsewhere. They are sometimes found in the adipose tissue adjoining the muscles. (39, pp. 87-93.) Those muscles adjoining the abdominal cavity are usually the most infected, especially the pillars of the diaphragm and the psoas, or tenderloin muscles. If half a dozen sections of either of these muscles be examined and no trichinae found, it will be pretty safe tc» conclude that the animal is not infected; yet these muscles may, in some cases, be almost or entirely free from the parasite, while others are infected, but such infections are generally quite light. The heart is nearly exempt from the invasion of the trichinae, only a few having ever been found within its muscles. Before encystment the embryos and migrating worms may be found in the intestines, in the pleural and pericardial cavities, in the connective tissue and muscle fibers. The central part of a muscle may be almost free from the worms, while the ends, or those parts near the tendons, are quite full. In making examinations it is best to take that part of the muscle near its origin or insertion. It is best, also, to examine the pillars of the diaphragm, or the psoas muscle first. If no trichinae are found in these, it is not probable that they will be found in other parts of the body. No domestic animal suffers more from contagious diseases than does the hog. It is estimated that the losses in the United States for 1877, occasioned by diseases of this animal, amounted to more than twenty million dollars, and for 1878, to 272 STATE BOARD OF HEALTH. more than thirty million dollarg. As is shown elsewhere, the hog is made sick by the invasion of trichinae, and, doubtless, in many cases his sickness, from this source, has been attributed to cholera, or some other disease. The cholera is a very distinct and different disease, however. With many hog raisers the temptation is very great, when a few of their hogs become sick, to hurry them into market or the pork barrel, for some one else to consume. It is unquestionably true that much diseased meat, of various kinds, is exposed for sale in our markets—far more than consumers imagine. NUMBER OF HOGS INFECTED. it is probable that in every part of the world where hogs exist they are, to some, extent, infected with trichina?. Gerlach gives a table of 664 infected hogs, found principally in Germany, from 1864 to 1874, inclusive. (104.) In the Duchy of Brunswick, from 1866 to 1876, 781,611 hogs were examined, of which 125 contained trichina?—250 were otherwise diseased and unfit for food. (111.) Berkan states that of 60,000 hogs killed in the four years preceding the year 1863, in Brunswick, seven were infected. In Blankenburg 8,000 were examined and nine found infected. Fifteen were found infected from other parts of the duchy. (14.) Of 67,427 hogs examined in Rostock, 1867-1877, 42 contained trichina*. (Petri.) (212.) Of 391,913 hogs killed in Gotha, 1865-1876, 46 contained trichinae. (Schu- chardt.) (239.) In 1876, 1,728,595 hogs were examined in Prussia, of which 800 contained tri- chinae. (78.) The highest degree of infection found in Guessin was 1 to 141. In 1877, 2,057,272 hogs were examined in Prussia, and 701 of them contained trichinae. (100.) In Stockholm, 1865-1875, 81,363 hogs, including whole hogs, halves and hams, were examined, and 143 were infected. (289.) Of 8,174 hogs examined in Copenhagen, 15 were infected. (140.) In Russia of 3,550 hogs examined 5 contained trichinae. (145.) In all places where examinations have been made, hogs fed in cities contained more infected animals, in proportion, than those fed in the open country. In 1879, 3,164,656 hogs were examined in Germany by 14,413 experts. Ameri- can hogs were found to contain trichinae in the proportion of 2 per 100 ; indigenous hogs 1 to 9 per 100. Nine per cent, of those examined were measly. (39, p. 209.) Measly pork is the source of infection for the tape worm, the larval form of this worm, cysticercus, causing the measels in hogs, and developing into tape worm in man. In France, of 50,210 pieces examined, 993 contained trichinae. Of 53,318 pieces examined, 1,087 contained trichinae. These purport to be from American hogs. (39.) No trichinae were known to exist in Europe prior to 1830 ; but, no doubt, it was owing to a want of observation and knowledge, rather than to their absence. It is probable they existed there long before, and that many persons died of trichinosis, whose deaths were attributed to other causes. TRICHINA SPIRALIS AND TRICHINOSIS. 273 There has, as yet, been no systematic examination of American hogs for tri- chinae. Isolated examinations have been made, here and there, and upon these we must base our estimates of the percentage of infection. The impression prevails in Germany, France, Italy, and elsewhere in Europe, that American hogs are more largely infected than those of any other country. This may be true as to certain parts of America; but is probably not true as to other parts. The percentage varies very much in different districts. I have collected the statistics of all ex- aminations made in this country, and of American hogs examined elsewhere, so far as I have been able to find them. Examination of American hogs, by the piece, in Prussia, shows an average of 4 per cent, infected. This does not show the absolute infection, for more than one piece may have been taken from the same hog. In Germany we find that of 170,- 382 hams examined 2,050 were trichinous; that of 60,341 sides examined, 551 were infected. At other European points, where examinations were made of American meats, we find that of 332 sides examined, 2 were infected. Of 5,673 pieces examined, 47 were trichinous. That of 103,528 pieces examined in France, 2,080 contained tri- chinae. (39.) The following is a table of all the examinations of American meats that I have been able to find ; TRICHIN.E IN AMERICAN HOGS. TABLE OF AMERICAN HOGS EXAMINED. No. Examined. No. Infected. Name of Examixer. Place. Where Reported, Etc. 88 14 Prof. Miiller Berlin .... Billings, 16. 400 (?) 00 Dr. Patton, 1881 . . Newspaper report. B’n M. & S. Jour., v.74,136. 1,328 28 Academy of Science 100 8 Belfield & Atwood . . Chicago . . . 13. 8,773 345 ••'Dr. P. S. Billings . . Boston.... 16. 5,400 330 22 + Dr. J. T- Payne . . . New Orleans. 209. 2 tDrs. Smith & Myers . Texas .... Georgia . . . 257. 30 00 Dr. C. A. Simpson . . 209, p. 138. 180 00 Prof. Stager Nashville . . 209, p. 138. 200 00 Dr. Ames New Orleans. 209, p. 135. 28 00 Dr. Billings tDrs.G.A W. E Sutton Boston .... 16. 1,000 245 68 Indiana . . . 259, p. 123. 40 Drs. Hardi’g & Rob’n Indiana . . 259, p. 124. 200 13 Drs.Gateh