The establishment of this species as distinct from T. solium is due to Küchenmeister; but it is curious to observe how accurately this determination was foreshadowed by the shrewd naturalist and theologian, J. A. E. Goeze, who clearly indicated two forms of the common tapeworm, remarking (l. c., Bibl. No. 1, s. 278):—“Die erste ist die bekannte grosse, mit langen dicken und gemästeten Gliedern, die ich Tænia cucurbitina, grandis, saginata, nennen will.” The same author (s. 245) pointed out the resemblance subsisting between the tapeworm of the cat (T. crassicollis) and the vesicles (“Krystallblasen”) and their contained “erbsförmige Blasen” (Cysticercus fasciolaris) of the mouse. Thus the celebrated pastor of St Blasius, in Quedlinberg, almost contemporaneously with Pallas, early arrived at the conclusion that the hydatid-measle was a kind of tapeworm.
Respecting the organisation of this worm I may observe that the mature joints have a more complicated uterine organ than obtains in Tænia solium, presenting nearly double the number of lateral branches. They are more closely packed, running outwardly in an almost parallel manner. The first sexually mature proglottis occurs at about the 450th joint, but whereas, in the pork tapeworm, only some 200 subsequent segments share this perfect character in the beef tapeworm, according to Leuckart, as many as 360 or even 400 mature joint may be present. The joints are very liable to form monstrosities; these abnormalities sometimes affecting the reproductive organs, which become doubled or even trebled. In the Hunterian collection there is a proglottid showing twenty-two sexual orifices. Dr Cullingworth, of Manchester, has described a specimen in which the joints are curiously tripartite.
As already hinted the true source of this parasite has been proved by experiment; the first successful worm-feeding having been accomplished by Leuckart. Mosler’s, and subsequently my own feeding experiments, immediately followed. Other successful experiments with this species have been conducted by Zurn, Probstmayer, St Cyr, Perroncito, Masse and Pourquier, and Zenker. As will be again mentioned below Dr Oliver, R.A., whilst stationed at Jullundur, successfully reared the adult tapeworm in a Mohammedan groom and in a Hindoo boy. It will also be seen that Prof. Perroncito reared the worm in a student in fifty-four days. In my own experiments on animals I was assisted by Professor Simonds. The feeding materials were tapeworms expelled from my own patients. We obtained the following interesting results:
Exp. 1.—A calf. First feeding, Dec. 21st, 1864. Marked symptoms. Slaughtered April 3rd, 1865. Result positive.
Exp. 2.—A calf. First feeding, April 13th, 1865. Second, third, and fourth feedings in May and June. No symptoms. Died on Sept. 3rd, 1865, after thirty-six hours’ illness with “cattle plague.” Result stated to have been negative as far as the muscles were concerned. Viscera not examined.
Exp. 3.—A Dutch heifer. First feeding, March 3rd, 1865. Three subsequent feedings. Symptoms only slight. Slaughtered April 4th, 1866. Result positive. Measles especially numerous in the diaphragm, but all had undergone calcareous degeneration.
Exp. 4.—A calf. Fed May 27th, 1872, with ripe proglottides. Marked symptoms set in on June 7th, which began to abate on the 12th, and had nearly disappeared by the 20th of the same month. The record of the post-mortem result has been lost; but the animal was infected.
Exp. 5.—A calf, which had been made the subject of a “glanders experiment.” First fed on Oct. 17th, 1872, and thrice in the following year, Jan. 1st and 11th, and March 8th. No symptoms having appeared the animal was kept for six or eight months after the last feeding. Seeming to be free from disease of any kind, it was sold as a sound heifer.
Exp. 6.—A young heifer calf, of six months. Fed Oct. 18th, 1873, with the mature proglottides of a large beef tapeworm. No symptoms. Slaughtered several months afterwards. Result stated to have been negative. Unfortunately I was not present at the autopsy.
Exp. 7.—A young heifer. First fed May 19th, 1874, with the joints of a tapeworm, and again on June 12th. No apparent ill effects resulted, but the animal died in October. At the post-mortem examination, made by Prof. Simonds, no parasites were observed. Subsequently I found calcareous specks in the liver which proved to be degenerated measles.
Exp. 8.—A calf. Fed on or about March 24th, 1875, with sexually mature joints. The calf was put to and remained with a foster mother until it died from disease of the larynx on the 15th of the following July. The animal was ill-treated by its foster parent, and at the post-mortem I observed a large intercostal cicatrix, evidently the result of injury. In this case I devoted several hours to the exploration of the muscles and viscera. Not a trace of the Cysticercus bovis could be found in the muscles or connective tissues, but the liver contained scores of perfectly developed measles, besides hundreds of others in various stages of calcareous degeneration. On comparing some of the latter with those I had obtained from the preceding experiment the pathological appearances were at once seen to be identical. It was easy to find and pick out the measles in their cysts from the naturally friable liver. I also detected four Cysticerci in the lungs, two of which had degenerated. Microscopic examination confirmed my interpretation of the naked-eye appearances.
Fragmentary as the above data are, they serve to show that we have hitherto been too hasty in concluding that beef and veal measles reside only in the voluntary and striated muscles of their hosts. The facts here recorded prove that the liver of a calf may be extensively invaded by cysticerci, and yet the animal will exhibit no sign of constitutional disturbance. The cestode tuberculosis may come and go without any diagnostic symptom, whilst a few months suffice for the natural death and decay of the parasite by calcareous degeneration. Thus it becomes extremely probable that many experiments hitherto regarded as negative in their results have really been positive; the pathological evidences having been either misinterpreted or altogether overlooked. Every pathologist is familiar with gritty particles in the various viscera of man and animals, but few are probably aware how constantly these are dead and degenerated Cysticerci. The gritty particle itself may be reduced to the merest point, no larger than the receptaculum capitis of the Cysticercus itself, and in course of time it will disappear entirely. Practically it is satisfactory to have experimental evidence of the fact that cattle, as well as other animals, however extensively measled they may have been, can become thoroughly cleansed of the disorder by nature herself. It is only necessary that the diseased animals be separated from infectious influences.
Although the beef measle has never yet been found in man, I have for convenience sake introduced the facts of larval parasitism in this place. The sanitary bearings of this subject are far too important to be dismissed in a summary manner. I have shown that the prevalence or rarity of the beef tapeworm in man is strictly dependent upon the habits of the people; this same cause operating to produce healthy or diseased meat-food, according to the degree of civilisation. In this connection the oft-quoted statements of Kaschin respecting the prevalence of tapeworms among the Burätes, and the well-known frequency of this entozoon in Abyssinia, need only be alluded to.
When discussing the food question in my ‘Manual,’ I freely availed myself of facts privately communicated by Dr Joseph Fleming, and I especially referred to the published labours of Lewis, Hewlett, Veale, and other observers stationed in India. Beef measles are extremely common in the cattle of the north-west provinces of India, so much so that severe restrictions have been imposed upon the consumption of ration beef. The presence of a few measles in the flesh of cattle has been deemed a sufficient excuse for condemning and burying entire carcases. The measle is easily distinguished from that of mutton and pork by the fact that its head is not furnished with hooks, whilst in the place of a rostellum there is a small, centrally placed, retractile disk, which assumes the appearance of a supplementary sucker as in the adult worm. The four true suckers are also comparatively large. The measle usually varies in size from the fourth to the half of an inch in length, but my cabinet contains a specimen nearly an inch long. This was contributed by Dr J. Fleming, who mentions having seen a measle which, when unrolled, measured nearly an inch and a half in length. Although thousands of these bladder worms must exist in the cattle of England, up to the present time not a single instance has been recorded of the occurrence of these cystic parasites in the United Kingdom, except in our experimental animals. Notwithstanding my inquiries, I have not yet found a butcher, flesher, meat-inspector, or veterinarian, who has encountered this parasite in any animal slaughtered for the market. Several butchers have denied their occurrence in meat sold by themselves. Even so late as June, 1874, the presence of measles in the flesh of cattle was denied before an assembly of French savans; yet for many years past I have constantly exhibited measly beef and veal in the lecture room of the Royal Veterinary College. (See the discussion of the Société de Thérapeutique, recorded in the ‘Bullétin Gén. de Thér.’ for June 30th, 1874, and also the ‘Jour. de Thér.,’ No. 14, for July, p. 556, where, however, special remarks on this head have been omitted; see also the ‘Lond. Med. Record’ for July 29th, 1874, p. 472, and the ‘Lancet’ for Dec., 1874, p. 794.) Quite in contrast with the statements referred to are those of recent Italian observers.
Some few years back Professor G. Pellizzari communicated to the Medico-Physical Academy, at Florence, the results of a series of experiments conducted by himself, with the assistance of Dr Tommasi, in regard to the temperature necessary for the destruction of cysticerci in measled meat. An account of these experiments is published in Tommasi’s edition of my ‘Manual.’ The researches were made in relation to certain sanitary measures effected by the Municipal Commission of Florence, the express object of these measures being to prevent the injurious distribution of measly meat, especially that of swine. Signor Bosi, the superintendent of the public slaughterhouses, granted every facility in his power. In a previously published memoir by Professor E. Perroncito it was stated that measly meat (panicatura degli animali) required a higher temperature than that of boiling point for the destruction of the bladder worms in question. In this opinion Signor Bosi shared. According to the original memoir of Perroncito we are told that “about twenty specimens of Cysticerci were collected by the author, and placed in boiling water. After twenty minutes’ boiling, not one of the parasites appeared to suffer. The head continued to be drawn into the body, and when the Cysticerci had their heads drawn out one by one they still appeared to possess all the elasticity of living bladder worms, displaying those movements of extension which are proper to parasites not yet dead. The hooks were observed regularly disposed on the proboscis, where they formed a double crown, the suckers remaining intact.” Perroncito remarked, however, that the Cysticerci showed a coloring tendency towards brown, and he added that “with the aid of two needles it became easy to lacerate the body of the Cysticercus, which appeared to be swollen, and possessed of diminished cohesion of its parts.” It was evident to all eyes, observed Professor Pellizzari, that these statements involved clear contradictions. Yet again, at page 28 of the memoir, Professor Perroncito wrote:—“During the past winter I introduced some little slices (fettuccie) of muscle-flesh (8 to 10 millimètres in thickness), infested with Cysticerci into a vessel (cassolina) containing fat at the temperature of 190 to 200° Cent. (374 to 400° Fahr.). At the expiration of ten or fifteen minutes the slices of meat were fried, and the Cysticerci lying at the surface had acquired a light brownish colour, as if they were roasted. By breaking up the slices one could still see the small reddish muscular bundles, whilst the Cysticerci in the middle remained entire and well preserved. Their heads displayed the hooks and suckers regularly distributed.” It is certainly singular, as Pellizzari observes, that these Cysticerci, having been thoroughly fried and roasted, should still remain alive and in their normal state; but the ultimate conclusion at which Perroncito arrived was still more startling, and one which, if it were true, would not fail to create a considerable stir among our officers of health. On reviewing the whole matter Perroncito says:—“It appears to me that the melted fat alone of hogs (maiali grandinosi) should be utilised, and I am pleased to reckon the illustrious Gerlach and all other distinguished practitioners to be of the same opinion. Permit me, therefore, being well satisfied also with the results of many other experiments, once more to advance the conclusion that, if it is not certain that the Cysticerci die at from 80 to 100° Centigrade (176 to 212° Fahr.), we are quite sure that they dry up and become completely mummified at 125, 130, and 150° Cent. (257, 268, and 302° Fahr.), temperatures which we could easily produce by means of a properly constructed apparatus.”
After remarking upon the serious nature of the conclusion which Perroncito sought to establish, Professor Pellizzari makes further use of quotations which bear upon the question as to whether the quality of the vessels in which the fat of diseased hogs is melted down may not largely affect the degree of high temperature sought to be obtained (in view of a perfect destruction of the Cysticerci). Perroncito repeatedly witnessed the operations of pork-butchers; and when portions of meat were introduced, with water, into the cauldrons, he always saw that the temperature “was maintained between 97° and 98° Centigrade.” However, this part of the question may be dismissed in a very few words, since Perroncito himself finally allows that “the different composition of the vessels cannot elevate the temperature of the fat by many degrees.”
With the praiseworthy intention of either verifying or refuting these conclusions, Pellizzari, with the approval of Bosi and with the assistance of Tommasi, instituted a fresh series of experiments at a private laboratory. The details of these experiments are exceedingly interesting; but as their record occupies several pages of Tommasi’s appendix already referred to, I must content myself with a general statement of the results obtained. Professor Pellizzari found that Cysticerci, so far from requiring a temperature of upwards of 100° Centigrade for their destruction, die at a temperature of 60° Centigrade (140° Fahr.). He had, it appears, previously taken the initiative in recommending certain measures to the Florentine municipality, in view of protecting the public health, and he had now the satisfaction of more than confirming the wisdom of these sanitary precautions. In excessively measled animals the fat is removed and boiled in suitable cauldrons, and has potash mixed with it to render it useful for industrial purposes. By the various measures adopted the entire animal is utilised, and with proper precaution there seems little chance for the measles to arrive at the tænioid or sexually mature condition.
In the next part of his communication Pellizzari touches upon the question of measles in beef, referring especially to the experimental labours of Leuckart and myself. Finding additional support from our views Pellizzari declared the propositions of Dr Perroncito as of no value whatever. “But how is it,” he adds, “that notwithstanding that so low a temperature suffices to kill these cysticerci, yet cases of Tænia are continually occurring?” The answer to this question will appear in the sequel; but meanwhile it will be as well to refer to the recent brochure by Dr Giacomini. This author appears to have had no opportunity of perusing Pellizzari’s communication already cited, and consequently it is not surprising that he should, in common with others, have accepted the original conclusions of Perroncito. Dr Giacomini clearly perceives that, whatever precautions of a hygienic character are suitable for the prevention of disease arising out of the consumption of measly pork, the same, or at all events similar, measures ought to be adopted with the view of checking tapeworm affections arising from the ingestion of other kinds of meat, especially veal and beef. Like Pellizzari, he is satisfied as to the human origin of the small bladder worms found in cattle, and establishes this position not only from the oft-quoted experiments of Leuckart and Mosler, but also from those conducted by myself and Simonds in England, and by Professor F. Saint-Cyr in France. From a careful review and consideration of all the facts of the case, he recommended a more complete supervision over the flesh of oxen before it is employed commercially, and greater precaution when employing veal as food, by causing it to be subjected to a high temperature, in order that the parasites may be killed before it is ingested. It is evident that Giacomini thinks that a temperature exceeding that of boiling-point is necessary for the destruction of the beef and veal measles, since he immediately adds, “Though experiments have not been made with the object of ascertaining the amount of resistance of heat which the unarmed cysticercus can bear, yet, judging by those conducted by Professor Perroncito on the measle of the hog, we are in a position to say that a temperature of 135° Cent. (275° Fahr.) is necessary for the destruction of an isolated Cysticercus, whilst the heat should be raised from 150° to 200° Cent. (302° to 392° Fahr.) for ten or fifteen minutes, in order to ensure the complete destruction of the Cysticerci encapsuled in the interior of a piece of meat.” I have abridged this portion of Giacomini’s text, because his statements are pretty much the same as those already quoted from Perroncito (as cited by Tommasi). But, in the next place, Dr Giacomini is in error when he states that experiments had not been performed on the Cysticerci of the ox. So far from this being the case, similar experiments had long previously been conducted by Dr Lewis in India; and these researches had quite as much to do with the measles or Cysticerci of beef as they had with those of the hog, if not more. Naturally but few foreign investigators can have had access to the work in which Lewis’s experiments were originally recorded, and to which, therefore, I must call their attention. Thus, Dr Tommasi has fallen into the error of supposing that the investigations of Lewis were made in England. It is of very little moment where the experiments were carried on, but Tommasi’s statement (appendix, loc. cit., p. 161), wherein he says that Pellizzari’s experiments, in which he himself took part (ai quali io stesso ho assistito), are even more complete than those made in England by Dr Lewis, and in Germany by Dr Küchenmeister, cannot be allowed to pass unchallenged. If Tommasi had enjoyed the opportunity of consulting Lewis’s original memoir, he would not have underestimated our countryman’s labors. The memoir by Lewis is singularly complete, and well-nigh exhausts all the facts that can have any interest in relation to the question of public health. Towards the close of his essay he expressly states, as the result of investigation—“(1) That exposure to a temperature of 120° Fahr. for five minutes will not destroy life in Cysticerci, but that they may continue to manifest indications of life for at least two or three days after such exposure; (2) that exposure to a temperature of 125° Fahr. for five minutes does not kill them; but (3) after being subjected to a temperature of 130° Fahr. for five minutes, they may be considered to have perished. After exposure to this and higher temperatures, in no instance have I been able (he adds) to satisfy myself that the slightest movements took place in their substance when examined even under a high power. At least, it may be confidently asserted that, after exposure for five minutes to a temperature of 135° to 140° Fahr., life in these parasites may be considered as absolutely extinct” (p. 139). Thus the statements of Lewis and Pellizzari were in perfect accord; and seeing that their conclusions were alike the result of very careful and independent inquiry, it seemed as if the question at issue was finally solved. These investigations made it perfectly clear that Cysticerci of all kinds, whether found in veal, beef, or pork, could not retain their vitality when exposed to a temperature of 60° Centigrade, or, in other words, 140° Fahr.
The rather severe strictures made on Perroncito’s earlier experiments induced the Turin professor to go over the subject more carefully, when he obtained excellent results. He finally ascertained that Cysticerci perished at a temperature below 50° C. (122° Fahr.). In May, 1877, Dr Perroncito furnished me with an account of his researches. With the exception of a few verbal alterations, for which I am responsible, Perroncito wrote as follows:
“In order to resolve the highly important question of the tenacity of life of the Helminths and corresponding larval forms, I made since 1871 a very long series of experiments on the Cysticercus cellulosæ, which were published almost at the same time with others of the same kind, made by Dr Lewis in Calcutta. Towards the end of 1874 Mr Pellizzari, of Florence, disputed the results of the investigations which I had made known two years before, i.e. in 1872, and agreed with Dr Lewis, who had stated already that the Cysticercus exposed to a temperature of 55° C. can be held for dead after five minutes, and also with Dr Cobbold, who thought the temperature of 60° C. quite enough to kill it. But the characters he (Mr Pellizzari) relied upon, needing the exactness and precision required to enlighten and persuade in the most important scientific questions, gave rise to a mistrust in the most scrupulous amongst the men devoted to biological pursuits and to several hygienic measures on the part of the sanitary inspectors with regard to infected pork. Therefore, my conclusions, argued from the experiments made in 1871–72, were still those followed by the most important Italian cities, and approved in principle by the superior Board of Health in 1873. I expressed doubt then about the Cysticercus dying at a temperature lower than 100° C., and some person misconstrued these doubts, saying that I had contradicted myself in my work. However, as I could not assert they died at 80°–100° C., I only noticed the alteration of color and cohesion which happened in the Cysticercus exposed to various degrees of temperature, to the end that I might contribute usefully to the solution of the difficult question, and concluded that ‘if we could not be sure of the Cysticercus dying at 80°–100° C., it was certain at all events that they perished at 125° or 130° C.’ Not wishing to prejudice the question, I never said that they did not die at 80°–100° C., but simply stated that at this temperature we could not be certain of their death.
“Now, after a large number of experiments, I have been able to ascertain with exactness the lowest degree of temperature required to kill infallibly the Cysticercus and other parasites of animals. The means I made use of for this kind of investigation were Mr Schulze’s heating table, the neutral tincture of carmine, the tincture of hæmatoxylon, and breeding experiments.
“My method is founded essentially—
“(a) On the fact that the Cysticercus when it is fresh and is stretched and conveniently prepared in pure water, or in chloride of soda very much diluted, and afterwards brought gradually from the temperature of the ambient air to that of the body of higher animals and to degrees of heat still more elevated, until life is extinct, keeps moving to and fro with more or less energy throughout its body, using especially its suckers and proboscis.
“(b) On the greater imbibing power of the dead tissue generally, which is undoubtedly far more apparent in insects and plathelminths.
“(c) On the experiments made to ascertain the value of the two above-stated facts.
“If, after having prepared a Cysticercus, newly extracted from a pig in the way we have pointed out, we examine it with a microscope on M. Schulze’s heating table, we find that usually it begins to move after 30° or 35° C., and each moment with greater activity, especially after 38°, 40°, 42°, 44°, 45° C. The temperature being raised progressively, we see that the Cysticercus cellulosæ puts a stop to its movements occasionally at 45–46° C., seldom at 47° C., more frequently at 48° C., sometimes at 49° C.; and, in fifty and more experiments, only one Cysticercus was able to live on beyond 49° C., standing still at 50° C.
“As soon as it stands still the parasite is dead. In fact, if we lower again the temperature gradually to that of the ambient air, and if afterwards we raise it a second time, we pass through all the intermediate temperatures without the Cysticercus showing the least signs of life.
“But a more convincing proof of the death of the parasite is got from the greater imbibing power of the tissue when life is extinct, the same over the whole body of the plathelminths, and their larval forms. If we dip the Cysticercus alive with its head stretched in the neutral tincture of carmine or hæmatoxylon we can leave it there even two, four, eight, ten, or twelve hours and more, without the head coloring or a real imbibition taking place; this begins only after the Cysticercus is dead, so that if the Cysticercus is brought first to a temperature hot enough to kill it (with M. Schulze’s tables to one of 48°, 49°, 50° C.) and dipped afterwards in the above-mentioned tinctures, it colors intensely in less than 45°, beginning from the head, and onwards to the extremity of the cyst of the tail. The head colors more intensely and rapidly than the neck, as it is covered with very numerous calcareous corpuscles, which are not met with so frequently in the remaining part of the body.
“Cysticercus cellulosæ of the pig, and that of the Tænia mediocanellata of the calf, brought gradually to a final temperature, the first of 50° C., and the second of 44°, 45°, and 47° C., and then swallowed alone, or with a piece of butter or crumb of bread, never produced the Tænia in the valiant students who voluntarily undertook to make the experiment of swallowing them.
“My investigations were extended to other kinds and forms of Helminths, and the results were always the same, so that, abiding by the same principles, I was able to ascertain that—
“1st. The Cysticercus cellulosæ of the pig dies sometimes at 45° C., more frequently at 47° C., ordinarily at 48° C., very seldom reaches alive 49° C., and is quite an exception when it resists for a few moments the temperature of 50° C., so that we can say that the Cysticercus brought gradually up to this temperature most assuredly dies if it is kept there longer than one minute.
“2nd. A Cysticercus cellulosæ, extracted by Professor Raymond from the conjunctiva of a child’s eye, died between 45° and 46° C.
“3rd. The Cysticercus of the Tænia mediocanellata dies sometimes at 44° C., very often at 45° C., and does not resist a temperature superior to 46° C.
“4th. The Cysticercus pisiformis of the rabbit, like the cellulosæ, dies sometimes at 45° and 46° C., but generally stands still and perishes at 47° and 48° C.
“5th. A Cysticercus tenuicollis died at 49° C.
“6th. The scolici of the Cœnurus cerebralis of a sheep died at 42° C.
“7th. The scolices of the cysts of Echinococcus polymorphus die generally between 47° and 48° C., and in no case amongst those I have experimented on did it reach 50° C. alive.
“8th. The Tænia cucumerina died, one at 43° C., and a second parasite at 45° C.
“9th. A few individuals of Tænia serrata of the dog died at 50° C.
“10th. Two individuals of Tænia perfoliata of the horse died, the first at 45° C., the second at 50° C.
“11th. The embryos of the Filaria microstoma of the horse began to stand still at 46–47°, and all died at 48° C.
“12th. The embryos of the Filaria megastoma of the horse’s stomach died at 47° C.
“13th. The Trichina spiralis, both free and in a cyst, in several experiments always died at 48° C.
“14th. The embryos of the Strongylus filaria of the sheep stood still at 50° C.
“15th. Probstmayer’s viviparous oxyurids, the infusoria of the colon and cæcum of the solipeds, and the psorosperms of the liver of the rabbit did not stir at all.
“Each experiment lasted about ten minutes, and the temperature rose from 8–10° C. to 45–46° C. in six to eight minutes; and from 46° to 50° in one minute. These experiments have a great value, both scientific and practical, as they show, on one side, which is the lowest intensity of heat sufficient to kill always the Cysticercus, the Trichina, and other parasites, reducing thus by far the tenacity of life generally attributed to a large number of Helminths and corresponding larval forms. They assure us, moreover, of the harmlessness of the flesh infected by the above-mentioned parasites, when it is cooked in such a manner as to reach the temperature of 50° C. over all points of the pieces, even though it be kept at such a degree of heat not longer than five minutes.
“In a piece of leg of pork the Cysticerci were found alive in all places not yet putrefied twenty-nine days after the animal had been slaughtered. On the other hand, in the dry muscles of a calf the Cysticerci of the Tænia mediocanellata were all found dead fourteen days after the slaughtering of the animal. I have ascertained that putrefaction of the flesh is fatal for the two larval forms of these different kinds of helminths.”
In a subsequent communication received from Professor Perroncito towards the close of the year 1877 he writes:
“At the last meeting, held on April 23rd, I made a statement to the Medical and Surgical Society of Turin, of the results of other experiments tried by heating at M. Schulze’s table and by the imbibitions with the neutral tincture of carmine, through which I came to the conclusion that the Cysticerci of the Tænia mediocanellata die sometimes at 44° C., now and then at 45° C., and always at 46° C. I therefore concluded that they could in no case survive at 47° C. and 48° C. when they were maintained at this temperature at least five minutes. But to the end of more fully corroborating the facts I had thus communicated, I, contemporaneously with these, made some breeding experiments with the same Cysticerci on bold and courageous students who generously offered themselves for the benefit of science.
“Consequently I am now enabled to state that neither Mr Gemelli nor Dr Ragni contracted the Tænia, though each of them had eaten a Cysticercus of the Tænia mediocanellata previously, and respectively subjected to a temperature of 45° C. and 47° C. The larvæ were properly prepared and submitted to gradual heating on the above-mentioned table, and swallowed when they no longer gave signs of life. In like manner no generation of the Tænia took place in the body of Mr Martini, who ate the Cysticercus brought to a temperature of 44° C. It was maintained at this degree of heat during a period of about three minutes, and swallowed whilst a very slight movement was still visible in a portion of its neck.
“In another student, on the contrary, who ate a living Cysticercus of the Tænia mediocanellata, the tapeworm reached its maturation in fifty-four days and eliminated the two first proglottides. It threw off two more on the fifty-eighth day, and thirty on the sixtieth. Sixty-seven days after swallowing the Cysticercus this courageous young man, having, like his three companions, taken some kousso and castor oil, emitted the strobila. It was furnished with 866 rings, but destitute of the neck and head. Its measurement afforded a total length of 4·274 mètres.
“Adding now to the 866 proglottides the thirty-four already eliminated, 900 would be the number of the segments; and reckoning the length of each of the latter to be fourteen millimètres, we should have had the strobila (deprived of the head and neck) reaching a length of 4·75 mètres. Further, calculating the head and neck to be eight millimètres long, a total length of 4·83 mètres would be the result.
“From all these facts we may conclude that the Tænia has, in our instance, reached an approximative length of seventy-two millimètres a day, affording a daily production of 13·43 proglottides.”
In relation to requirements of state medicine I have thought Perroncito’s researches sufficiently valuable to be quoted at some length; but their chief interest culminates in the worm- feeding experiments. Excellent in all respects as was the conduct of the medical students who, with Professor Perroncito’s approval, swallowed living specimens of the Cysticercus bovis, the intentional ingestion of beef measles is by no means a novelty. Eight or ten years back Dr Oliver (after explaining to one of the selected victims the possible consequences of the experiment) induced a Mahommedan syce or groom and a Hindoo boy to swallow perfectly fresh and living beef measles. In this way Dr Oliver successfully reared the Tænia mediocanellata in India, and he was thus enabled to fix the amount of time necessary for the full growth of the strobila. Many other persons have displayed an equal amount of zeal in the cause of helminthology, by partaking of the larvæ or germs of other parasites. Thus, at the risk of repetition, I may state that Möller many years ago swallowed the slender-necked hydatid (Cysticercus tenuicollis) in the hope of infesting himself with Tænia marginata. Several persons have defiantly swallowed trichinised flesh. Professor Leuckart and some of his pupils also courageously swallowed the eggs of Oxyurides, and they had the infinite satisfaction of noticing the young worms in their fæcal discharges some fifteen days afterwards. Dr Crisp ate part of the cooked flesh of an animal that had died of cattle plague, and I myself partook of moderately cooked meat which I knew to be swarming with psorosperms. These obscure organisms were by some persons considered to be either a cause or product of the rinderpest. They will be noticed in my account of the Protozoal parasites.
For the purpose of advancing science and the welfare of the people, there are scores of persons always to be found ready to make personal sacrifices of the kind undertaken by Drs Ragni, Martini, and Gemelli. Unfortunately for English science there are not wanting people in this country who are prepared to threaten with fines and imprisonment any savant who may think it desirable to perform a similar set of feeding experiments on animals. Invaluable for good as our experimental investigations have already been, it would seem as if it were the deliberate aim of these sentimental obstructives to put a stop to the acquisition of all useful knowledge in the future.
In reference to the rate of growth of tapeworms, Professor Perroncito’s determinations are useful, inasmuch as they verify certain ascertained facts with precision and confirm the general conclusion that had been drawn by practical helminthologists from various sources of information. In regard to the number of proglottides proper to a sexually mature tapeworm, the circumstance that Perroncito’s calculation was made without the head and a portion of the neck of the worm being present shows that it cannot be relied on absolutely; nevertheless, as far as it goes, it tends to confirm what Leuckart had long previously stated. I have possessed myself of upwards of thirty perfect beef tapeworms expelled from my patients, and in some of the specimens it was noticed that the segmentation-rings in the region of the neck were far more crowded together than they were in others. I also possess a perfect Tænia mediocanellata, removed post mortem. Though the rate of growth may be the same from day to day, yet experience has shown that the number of proglottides actually cast off varies exceedingly. Küchenmeister’s estimate of the average number agrees in the main with what we have ourselves observed (five to twenty daily); and here again Perroncito’s investigations serve to verify the general correctness of our previous determinations.
To return to Pellizzari’s researches, one of the most important questions is that which relates to the prevalence of tapeworm. In this connection he first brings forward some very interesting and instructive data that had been previously communicated to the Medico-Physical Academy of Florence by Professor Marchi. On the occasion referred to Marchi had stated that, out of thirty-five Tæniæ which he had examined, only one belonged to the species known as Tænia solium; all the other thirty-four being of the unarmed type, or Tænia mediocanellata. Reflecting on this striking fact, and also on the circumstance that he had in vain begged his colleagues to send him specimens of Tænia solium, Marchi seems to have missed the very palpable explanation of this otherwise strange phenomenon. “How does it happen,” exclaimed Marchi, “that, notwithstanding the occurrence of 13,000 kilogrammes of the flesh of measled hogs in the public butcheries, I have seen but one specimen of Tænia solium, whilst thirty-four cannot have originated from the pig?” “The wherefore is obvious enough,” replies Pellizzari, “because our hygienic regulations demand that the flesh of the hogs be raised to a temperature of 60° Cent. (140° Fahr.);” and he then himself immediately proceeds to ask another question, namely, as to how it happens that the Tænia solium is so frequently seen in other places. To his own question Pellizzari responds by remarking—(1) that there are not so many precautions (of a sanitary kind) taken in other places; and (2) that the people elsewhere consume more slightly salted or uncooked meat, as sausages and so forth (come salame giovane, salciccia e via dicendo). Pellizzari, having explained that Marchi’s thirty-four tapeworms must all have arisen from the consumption of the Cysticercus of the ox, then goes on to speak of the prevalence of tapeworm in Florence, even in little children. This last-named feature, he says, is due to the circumstance that raw meat is frequently employed as a restorative (come cura ricostituente). “Thirty years ago,” remarks Professor Pellizzari, “it was just as difficult to find a single Tænia mediocanellata as it is now easy to find a great number of these worms; and all because it is nowadays customary to eat the flesh of the ox either insufficiently cooked or raw. This absolute inversion of the facts of the case affords proof of the correctness of the position sustained by me, to the effect that the cooking of meat up to the degree of temperature necessary for ebullition ensures the destruction of the Cysticerci.” Notwithstanding this statement of his own, Pellizzari thinks that the interference of inspectors may be pushed too far, and thus serve to bring about the very disasters which it should be their supreme object to prevent. Thus, he argues against the suggestions of those who would entirely prevent the sale of measly meat, and who would only permit, as obtains in the province of Modena, the melting down of the fat of hogs. Very strict measures of this sort would, as he says, constitute a radical means of entirely stamping out Tænia, but he also very judiciously reminds the sanitarian (igienista) that “such a step would be a serious thing for the tradesman, bringing injury not only to the municipal administration, but also proving an encouragement to smuggling. In this way the public health would sustain worse injury by the inducement held out to the owners of infected animals to slaughter them in secret butcheries, thus little by little withdrawing the meat from the superintendence of the public officials. By the adoption of fraudulent measures there would be a daily consumption of diseased meat; and thus also, while the public administration would suffer loss, the public health, on the other hand, would gain nothing.” In effect Pellizzari says, if we advise the employment of more severe and radical measures than those already in vogue in Florence, we should overburden the tradesman, almost compel him to defraud the exchequer by smuggling, and greatly injure the public health.
The facts and explanations advanced by Italian writers regarding the causes of the endemic prevalence of tapeworm, are in perfect harmony with those previously obtained from other sources. Respecting these causes there is much that is both new and interesting. The eighth annual report of the sanitary commissioner of the Government of India had already made us acquainted with the fact that during the year 1869, out of 13,818 head of cattle slaughtered in the stations of the Upper Punjab, 768 beasts were found to be infected with measle-cysts. This, as I have remarked (Tommasi’s edit., p. 54), “affords a rate of 5·55 per cent., being a considerable diminution of the proportion observed in 1868, when the percentage gave a total of 6·12. The reduction was, without doubt, due to the vigilance and enlightenment of the army meat inspectors. The prevalence, however, of tapeworm does not bear relation to the number of animals infested with Cysticerci so much as to the actual number of Cysticerci developed in infected animals. I have frequently pointed out the inadvisability of condemning and burying the carcases of measly oxen, whether there be few or many Cysticerci present, and I have stated, on trustworthy evidence, that even the presence of a few Cysticerci is deemed by some inspectors a sufficient reason for rejecting the entire animal. Such a waste should never be allowed. In regard to the numbers of ox-measles present in particular instances, I have elsewhere adduced some remarkable facts communicated to me by Dr Joseph Fleming, of the Indian Army Medical Staff. None of my experimental animals, though fed with scores of ripe proglottides, yielded such an abundance of Cysticerci as Dr Fleming encountered in Punjab cattle. In one pound weight of the psoas muscles Fleming counted no less than 300 Cysticerci.” From this it follows that the flesh of a largely infested animal is capable, under the circumstances of ration distribution and imperfect cooking, of originating numerous tapeworms.
Not many years back the leading medical journal of this country challenged me to produce evidence as to the injuriousness of beef and mutton from Cysticerci. The writer stated in his article that I had “failed to produce a single specimen of beef or mutton measles” which had not resulted from experiments conducted “at the Royal Veterinary College;” and he said, further, “that butchers, fleshers, and veterinarians were practically right in refusing to adopt the opinion of Dr Cobbold, that measled beef or mutton is produced to any great extent” independently. How palpably I endured a species of unjust reproach for being somewhat in advance of the knowledge current at the time may be gathered from the voluminous evidence which has since cropped up from various parts of the world. It was, indeed, mainly through experiments conducted at the Royal Veterinary College, and reported in the ‘Lancet,’ that professional men in India first became acquainted with the possibility of finding Cysticerci in beef.
The statements of Dr Joseph Fleming, who was one of the foremost in discovering cystic disease in cattle, have since received abundant confirmation. The Indian Government Reports given in the February issue of the ‘Madras Monthly Journal of Medical Science’ for 1873 are especially instructive. Referring to the prevalence of Cysticercus in the ration beef at Jullundur, in the Punjab, the Inspector General (India Medical Department) reports as follows:
“Cysticercus was first noticed here in the beef tendered at the Royal Artillery ration stand in May, 1868. For some two years previous to this date condemnations of cyst-infected meat had been frequent at Peshawur, Rawul Pindee, Meean Meer and several other stations in the upper part of the Punjab, and here I had often detected the parasite in meat exposed for sale in the bazaars, but no trace of it had been observed in the Commissariat beef, either by myself or any other medical officer who had preceded me.
“From May, 1868, to November, 1869, ‘cyst’ was more or less frequently found both at the Artillery and 92nd Highlanders’ ration stands; but since the latter date it has almost entirely disappeared.
“The following table shows the quantity of meat destroyed on this account during 1868 and 1869:
“The whole of this meat was otherwise well fed and of excellent quality. The waste of so much good food led me to make inquiries; 1st, as to the sources from which the cattle obtained the Tænia ova, and the best means for preventing their infection; and 2ndly, as to whether or not any evil results followed the consumption of this meat when properly cooked.
“From information obtained from the Commissariat Officer I found—1st. That the infected cattle had been purchased by native dealers from various parts of the district, not from any particular locality. 2ndly. That when brought in they were lean, and on an average required from two to three months’ feeding at the Commissariat cattle yards before they were fit for the shambles. 3rdly. That their food consisted of the grass they could pick up on the grazing grounds of cantonments, supplemented by such an allowance of grain and bhoosâ as their condition required.
“They were supposed to be watered at a trough with water drawn from a well, but on closely inquiring as to this, it transpired that they very frequently were taken to a large dirty tank near the yard for their water. The question which occurred to me was, were the cattle infected before their purchase by the Commissariat, or was there anything in their feeding to account for it after purchase? I am inclined to the latter opinion for several reasons, thus:—In the large number of the diseased cattle, the Cysticerci were of remarkably small size; many of them having no capsules, except such as were formed by the surrounding structures, and not being more than 18 to 14 of an inch in diameter. Although the dry food given to the cattle was doubtless good, still much of the water they got during 1868 was probably filthy. The tank previously referred to was situated close to the huts of the camel drivers. These men are all Mussulmans from Cabul, Peshawur, or thereabouts, and many of them are infected with Tænia mediocanellata. Human filth was often to be seen on the banks of the tank, and microscopic examination of mud and stagnant water taken from the margin exhibited Tænia ova.
“The conditions above shown must have been eminently favorable to keeping up a constant supply of ova, and the fact that Cysticercus entirely disappeared from amongst the cattle a few months after means had been taken to secure them a good supply of well water, seems to confirm the view that this tank must have been the source of a large amount of, if not all, the infection.
“It has been suggested that Cysticercus can be detected before the animal is killed by an examination of the tongue. In exceptionably severe instances this is probably correct, but then it would be equally observable in some other parts of the body. Major Biggs, Commissariat Officer here, tells me of an animal he saw at Rawul Pindee, in which immense clusters of cysts could be felt at the root of the tongue and under the skin in several parts. After examining a very large number of tongues of ‘cysted’ animals, my experience is that it is found in the soft muscles and cellular tissues at the root of the tongue, perhaps more frequently than anywhere else; but I have never seen a case in which there was a chance of detecting it before death.
“The most common situations in which it has occurred in the ration meat have been the gluteal, psoas, and lumbar regions. In many instances only from one to ten cysts have been found on cutting the carcase into small pieces, and I have no doubt that it often passed without detection.
“During 1868 and 1869 I from time to time obtained pieces of beef badly infected with Cysticercus, and made some experiments as to the results of its consumption under different conditions.
“After explaining to them the possible consequences of eating it a buttock of beef studded with Cysticercus was given to three natives of low caste. They all declared that they were free from Tænia, or, to use their own term, “Kadhu dana.” The meat they cooked in their own way. These men were under my observation for some six months. Two of them had no symptom of Tænia, but the third, who was a low-class Mahommedan syce, and had probably eaten the meat in a very raw state, developed a Tænia mediocanellata in about three months.
“My own sweeper ate this cyst-infected beef regularly two or three times a week for some months. He cooked it well generally as an ordinary stew, and has never shown a sign of having tapeworm.
“Into the food of a boy of low Hindoo caste, but who had never eaten beef, two scolices of Cysticercus were surreptitiously introduced, the result being that, between three or four months afterwards, he applied for some tapeworm medicine.”
[The two successful experiments here reported are evidently the same as those that I have referred to (p. 72) as having been performed by Dr Oliver, of the Royal Artillery, stationed at Jullundur. The report continues as follows:]
“Tænia mediocanellata is very common amongst the Mussulman population of the Punjab, and from reliable sources I am informed that the lower classes amongst them are in the regular habit of eating half-cooked beef; indeed, prefer it so, and it is amongst these people that tapeworm is so prevalent.
“But it is not only thorough cooking that is required to guard soldiers in India from the ill effects of eating measly meat; there is want of cleanliness in the general arrangements of the kitchens and serving of meals, which must offer great facilities for the introduction into the food of Cysticercus.
“Barrack cooks, unless constantly looked after, are utterly careless as to the washing of chopping blocks, tables, dishes, &c. The dish or pot cover on which the meat is placed when raw is often used without washing for serving the piece up for dinner, and I have myself picked up a Cysticercus from the table on which a cook was preparing food. The dangers too of the parasite being conveyed by the cook’s unwashed hands to the plates in which meals are served, and the common practice of using the same knife for cutting up meat, and afterwards, without washing it, for other culinary purposes, must not be overlooked. With good selection and careful feeding there seems to be every probability that Cysticercus would soon almost or completely disappear from our Commissariat cattle. If they were entirely stall-fed and watered from wells there could scarcely be a possibility of infection after their purchase.
“Perhaps with the trench system of conservancy, which will necessitate the growing up crops, a sufficient quantity of root and other green produce may be obtained from cantonment lands set apart for this purpose, to supply green fodder for the cattle.”
The important question as to whether the presence of cysts detected at the root of the tongue could be made available for the purposes of diagnosis was made the subject of special report through the agency of executive Commissariat officers, and they testified to its practical valuelessness in the following terms:
“Jullundur.—No appearance of cyst has been found at the root of the tongues of any of the cattle. A medical officer was asked for assistance in making search for the cysts, but he also found none.
“Rawul Pindee.—It is utterly impossible to discriminate before slaughter, from any outward symptoms, cattle that are cyst infected.
“Every endeavour has been made to discover by close and careful scrutiny before slaughter the cyst-infected cattle, but the result has been in no way satisfactory.
“Sealkote.—All endeavours to discover any symptoms of the infection by examination of their tongues, while the animals were living, have been unsuccessful.
“Mooltan.—The mouth and tongue of a large number of living cattle have been examined before slaughter, but in no single instance has the infection been so detected.
“Dr Ross’s plan of examining the tongues of all animals at time of purchase is not feasible, as they are usually very wild and frightened, and often dangerous to approach.
“Peshawur.—In probably 99 cases out of 100 it is utterly impossible to discover cyst infection in cattle previous to slaughter by examination of their tongues. In only one instance has it been so discovered, and that was from the animal’s having a number of small lumps over the body which were also apparent on the back part of the tongue. When the tongue is infected the ‘cyst’ lies so far at the very root of it that it cannot be seen in the live animal.”
From Mooltan a specially interesting report was made by Dr Alexander Neill, who says:—
“I have carefully examined the mouth and tongue of a large number of living cattle, and of those slaughtered for issue as rations, and in no single instance did I find such cysts. These cattle were healthy.
“In a case that died, and in which cysts existed, I could discover nothing abnormal in or under the tongue.
“If such ‘cysts’ exist, or if such enlargements of the sublingual glands are found, I argue that they are not a diagnostic sign of what is termed ‘cyst infection,’ or more correctly ‘Cysticercus bovis,’ for in the recent outbreak of cattle disease in England, one most prominent symptom of that disease was a bunch of grape-like swelling under the tongue, which in advanced cases suppurated, and to a casual observer would have been called cysts or ‘bags of matter.’
“If such swellings are found in a bullock that is sick, it is merely symptomatic of an inflamed condition of the whole mucous surface of the intestinal canal, and not of any localised disease, such as Cysticercus, the above-mentioned swellings being merely inflamed sublingual glands.
“In the pig the diagnostic sign of swellings of the glands or ‘cyst’ under the tongue is not found in ‘Cysticercus,’ and the disease called ‘measles’ is not ‘Cysticercus,’ but a mere superficial inflammation of the skin and a symptom of fever. ‘Cysticercus cellulosus,’ as its name shows, infects the cellular tissue only of the pig, and cannot be discovered in life by any abnormal condition of skin.
“In ‘measles’ these swellings are found, because intestinal mucous membrane sympathises with eruption on the skin and are then merely inflamed glands, not cysts.”
Dr Neill concludes his report by remarking that the larvæ of the beef tapeworm can “only arrive at maturity in the mucous membrane of horned cattle,” and not in the cellular tissue. This is an error on Dr Neill’s part; but in adducing these instructive extracts from the Government Reports my chief object has been to show the prevalence of Cysticercus in the North-West Provinces of the Indian Peninsula. I may say that a large proportion of my tapeworm-infected patients have been officers from the Punjab, and one of these victims told me that when he superintended the serving out of rations to the troops, “he (and those who acted with him) sent the meat away to be burnt, even when they only detected a single cyst in any given carcase.” It is needless to remark that such a waste of valuable food is altogether reprehensible.
Some people, including not a few of the profession, make light of the occurrence of tapeworm, and I have seen many patients who had been told by their usual medical advisers that the presence of the worms was of little consequence. To account for this wide-spread error there is some basis in the fact that by far the majority of infested persons suffer only the trifling inconvenience arising from the passage per anum of the proglottides; moreover, the less civilised the tapeworm-bearers happen to be, the less are they likely to suffer. The recorded experience of Kaschin, before referred to, where 500 hospital patients, in the Baikal district, had tapeworm, although all of them were being treated for other disorders, affords another argument tending to the same conclusion. On the other hand, amongst Europeans only a small percentage of tapeworm-patients suffer severely. But without trenching upon the symptomatology and prognosis of tapeworm disease, I may remark that I have (in my Manual) summarised the whole facts of cysticercal prevalence within the compass of two brief propositions:—1. The prevalence or the rarity of Cysticerci in cattle in any given country must be determined primarily by the habits of the people; for since the beef measle can only result from the ingestion by the ox of the eggs of the Tænia mediocanellata, it is clear that the degree of infection of cattle will correspond with the facilities offered by egg-dispersion. 2. It may be affirmed that the frequency of this particular species of tapeworm amongst the people occupying any given area will bear a strict relation to the amount of underdone measly beef consumed by the inhabitants.
Another question, and one of great interest to sanitary science, is that which I have raised in reference to the period that nature requires for the destruction of the Cysticerci, or, in other words, for the performance of a natural cure by calcareous degeneration of the parasites. I have shown that all kinds of tapeworm larvæ (measles, bladder-worms, cœnuri, and so forth) have a natural life-epoch assigned to them, and in one of my experiments on a Dutch heifer or young cow I demonstrated that a period of ten months was more than sufficient to ensure the perfect destruction of the Cysticerci of cattle. Moreover, this law or process of natural cure is not limited to cestode parasites, but affects all other kinds of internal parasites in one or other of their juvenile stages of growth. In the flesh of my experimental animal I estimated that there were not less than 12,000 of these degenerated Cysticerci. This positive contribution to our knowledge of the limits assigned by nature to the epoch of larval activity is not merely one of abstract scientific interest, but it has important practical bearings, inasmuch as it points out in what way an entire herd of cattle (known to be measled by the post-mortem examination of one animal previously selected for the purpose, or for that matter, by the rather barbarous act of excising and examining a fragment of the muscle of a living one) may be freed of its parasitic guests; and it also shows how all risk of propagating tapeworm, apart from the question of subjecting the flesh to a certain temperature, may be effectually prevented. The stockowner has but to remove his animals for six or eight months to localities where no fresh infection can occur, when, at the expiration of the time mentioned, all those Cysticerci that existed in the beasts at the time of the transfer will have perished. The flesh of the animals may then be eaten with impunity, whether well cooked or raw. This is an important teaching deducible from experimental inquiry, and I am rather surprised that it has hitherto escaped the notice of persons who, though they affect to ignore the value of scientific researches, are particularly anxious to parade their practical knowledge, which, unhappily, too often proves a mere cloak for ignorance.
The memoir by Giacomini already quoted (p. 65) affords interesting details respecting a case in which there was a most unusual degree of infection of the human body by Cysticerci. Dr Giacomini instituted a searching comparison between the human measles procured by himself and those of the pig sent to him by Professor Perroncito. In the human Cysticerci he noticed a greater adherence of the capsule to the enclosed measle, and he also observed that while the human measle-heads either displayed thirty-two, or in some few cases thirty-four hooks, in two differently sized circles of fifteen or sixteen each, the pig-measles, on the other hand, carried only twenty-four hooks to the double circle of equal circumference; consequently the hooks appeared to be more crowded together in the human parasite. This fact, Giacomini remarks, does not of itself constitute an essential specific difference, since variations of the kind not unfrequently occur in Cysticerci occupying one and the same host. Even the beef-measle is not necessarily confined to one species of host, since Zenker has succeeded in rearing it in a goat.
Although the substance of the above-recorded conclusions was originally communicated by me, anonymously, to a professional periodical, I have considered this work a suitable medium for a fuller discussion of the subject. Its importance in relation to the public health and the supply of meat-food has not received the attention it deserves.
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