These birds live almost entirely on earth-worms during a part of the year, and I wished to know whether they would serve as a host for the parasite, and thus be instrumental in spreading the disease. The trachea of robins differs from that of poultry in its size and anatomical structure, especially at its lower part, where the last ring dilates and forms a second larynx. Syngami generally collect from the lower part of the trachea to its middle, and the gapes is simply the effort of the bird to obtain more air through this passage, which is obstructed by these worms. It is evident, therefore, that birds which have a larger trachea would harbor a greater number of syngami without suffering from the gapes. We see this is the case in chicks after they are several weeks old, for syngami can often be seen in their windpipes by opening their mouths and straightening out their necks. Several worms can thus be seen in large chicks with very little embarrassment to respiration. It is also not improbable that although the embryos may penetrate the oesophagus, pass to the lungs, and thence to the trachea, the greater part may be coughed up and swallowed before they are able to obtain a hold on its mucous membrane. We know from an examina. tion of chicks that very many of them are thrown off in this way.

Experiment 14.-On July 4, at 5 p. m., fed a chick about four weeks old a large number of syngami just hatched, by turning the water containing them down its throat. On July 11, at 7 p. m., this chick commenced to have the cough or sneeze characteristic of the gapes. July 12 coughs much more. On July 13, at 9 a. m., eight days and sixteen hours after the feeding, I killed the chick and found one single and twenty-nine pairs of syngami.

Experiment 15.-On August 14, at 7 p. m., fed a young robin just from the nest a large number of embryo syngami, hatched in water, as in the preceding experiment. It was kept in a cage, hanging under a tree, and fed by the old bird. August 22 (morning), robin has some symptoms of the gapes, such as rapid breathing, an occasional gape and shake of the head, and is inclined to sit on its perch instead of standing up as usual. August 23, breathes more rapidly and is evidentiy quite sick. August 26, continues to grow weaker and breathes more rapidly, and at times gapes, but the gaping is not as prominent a symptom as in the case of chicks. On the morning of the 20th the robin died, the fifteenth day from the feeding. On examination three fair-sized syngami were found in the trachea, but not enough to fill it up, so as to produce much gaping.

Earth-worms from infected localities were sent to us by Dr. Walker, in order that we might confirm his results:

May 25.-Three chicks were fed with 8 worms each. One was killed June 4. No evidence of syngames in the entire trachea. Near the pharynx a few blood extravasations on the esophageal mucous membrane attracted our attention. When carefully examined several small nematode worms were found in the submucous tissue, filled with ova. They were not coiled up but lying in a wavy line. Whether these parasites were introduced with the earth-wornis is a matter of conjecture. June 23, the two remaining chicks were set free.

July 1.-Two chicks were fed for two days until one had eaten sixteen, the other eight worms. July 7, two were fed until each had consumed twelve worms. July 24, symptoms pointing to gapes were observed in two of these four chicks. One was killed July 23, and three pairs of adult syngames found in the trachea. The other gaped occasionally, but grew very fast. It was killed August 6, and one pair of large syngames found attached to the trachea.

This pair was torn to pieces on the following day, and the mass, in which were large numbers of eggs, kept in distilled water. On August 17 the embryos could be observed moving about in the shell. Two days later many had left the shell. Thus a period of thirteen days, with an average temperature of 80° F., was sufficient for their develop. ment. When placed in distilled water August 6, the stage of segmentation was not yet passed. Meguin mentions twenty-eight to thirty days as the time required for development at a temperature of 68° to 77° F. The temperature of our laboratory ranged from 76° F. during the day to 88° F. at night.

On August 19, three chicks, one three days old, and two over a week old, were fed with these embryos and ripe ova. They were suspended in water and injected down the esophagus with the aid of a pipette, each bird receiving about fifty individuals.

The younger chicks died on the 1st, 3rd, and 6th of September, respectively. In the last only one pair of syngames was found. Of

the two older chicks, one died September 8, without any worms in the trachea; the other was killed September 16, no worms found.

Thus our success was only partial, both in feeding earth-worms and embryos of syngames, while Dr. Walker obtained very positive results with both modes of infection.

The foregoing experiments show that earth-worms of infected places do contain the embryo. They also show that the earth-worm is not a necessary host, and therefore Meguin's views as given in the preceding report remain still in full force. The embryo is without doubt present in the earth worm for the same reason that particles of earth, leaves, &c., are present. The earth-worm in boring into the soil must frequently swallow the earth that lies in its way, as pointed out by Darwin. That ova of syngames should be swallowed in this way is quite natural; and the embryos may even be used as food, and in that case killed before they leave the alimentary canal of the earth-worm. So that the question whether earth-worms are really injurious to farmers in eating ova or embryos of syngames can hardly be decided in the affirmative from these experiments. To Dr. Walker, however, belongs the credit of having pointed out the interesting fact that earth-worms of infected grounds may produce the disease in chicks which feed upon them.

Dr. Walker examined the alimentary canal of infected earth-worms carefully and found therein parasites which he believes were the embryos of Syngamus trachealis. We examined a number of worms sent by him very carefully, but failed to demonstrate the presence of any embryo smaller than the nematodes, which were quite uniformly present in the body cavity and inhabit the segmental organs. These measured about .5mm (.02 inch) in length. Dr. Walker gives the length of the smaller embryo as .0118 inch. A certain gregarina (G. agilis?) was also frequently observed.

Dr. Walker also tried artificial culture of the embryos which he obtained from the alimentary canal of the earth-worm. For this purpose he used blood serum, into which they were placed and then kept in an incubator. The blood serum was changed every day. Some worms died within two days; others lived for five or six days, during which period he observed some to molt. The rapidity with which blood serum decomposes at a high temperature, the toxic effects of the products of putrefaction, and the poverty in respirable oxygen of this medium make such experiments difficult of execution and uncertain in results.

Dr. Walker suggests that the earth-worms of infected poultry-yards be destroyed. To do this the ground is to be covered with lime, salt, or ashes, of which substances he prefers the salt.

As to the possibility or desirability of exterminating the earth-worms from poultry-yards where gapes exist among the fowls, the experiments made are neither sufficiently numerous nor so definite in their results as to admit of a satisfactory conclusion. That chicks may contract gapes by feeding upon earth-worms that contain the embryos of Syngamus is demonstrated, but it has also been demonstrated that this is not the only way by which this parasite gains entrance into the body of the chick. To destroy earth-worms Dr. Walker recommends saturating the earth of poultry-yards with a solution containing 1 or 2 pounds of salt to a gallon of water. All interested in this subject should carefully read, in connection with the present remarks, the details of the measures of prevention suggested by M. Megnin (First Annual Report of the Bureau of Animal Industry, pp. 292-295); and in case of failure to arrest the disease by these measures, an attempt may be made to destroy the earth-worms according to the recommendations of Dr. Walker.

VERMINOUS BRONCHITIS IN CALVES AND LAMBS, AND ITS TREATMEMT BY TRACHEAL INJECTIONS.

The occasional appearance of the disease known as lung-worm disease in cattle and sheep, also called verminous bronchitis, the husk, hoose, parasitic bronchitis, phthisis pulmonalis verminalis, renders it important to put together whatever facts are known at present concerning the nature, cause, and treatment of the disease. The primary seat of the affection being the lungs, the disease might, on superficial examination, be confounded with the far more dangerous disease of pleuro-pneumonia, unless the symptoms and the means of diagnosis during life, as well as the appearance presented by the lungs on post mortem examination, be carefully noted. The life history of the parasites that are the cause of the disease is not yet fully known, although upon it depends the most important kind of treatment-that of prevention. The following pages contain the most advanced views, and it is to be hoped that the near future will convert these views into absolute facts upon which a rational prophylaxis may be based. The disease attacking sheep and goats is due to a nematode worm, Strongylus filaria; the parasite attacking calves, Strongylus micrurus, also found in the horse and ass, is closely related to the former. A third form, common in swine, Strongy lus paradoxus, does not appear to cause any serious disturbances in swine. In an apparently healthy, fat pig, which was killed at the experimental station last year for another purpose, plugs of these worms were found in the smaller bronchi, enveloped in mucus. In a severe case of swineplague, these same worms were found in the lungs plugging some of the smaller tubes. The lungs themselves were not hepatized, however, as is frequently the case in swine-plague, the lesions being limited mainly to the large intestine. Recently this parasite was found by A. Koch (Die Nematoden der Schaftunge, 1883) to infest in large numbers the bronchi of sheep in an epidemic of verminous bronchitis. The same observer also describes another parasite found in the lungs of sheep, the pres ence of which was characterized by nodular elevations on the surface of the lungs containing large numbers of hair-like worms (Pseudalius ovis pulmonalis).

The disease depends, according to most authorities upon the relative humidity of the soil, and is therefore most prevalent in low-lying, swampy pastures containing pools of stagnant water. Years of abundant rains are said to favor the outbreak of the disease for the same reason. Epizootics have, however, been observed in elevated regions, and in England it is asserted that hill farms suffer most from ravages of Strongylus filaria, the lung-worm of sheep. Davaine, eliminating the influence of moisture entirely, states that the only constant features of the disease are age and season. It is probable that outbreaks in elevated regions are exceptional and due to special causes. Young animals, calves from twelve to fifteen months old, and lambs, are most prone to suffer, yet cases have occurred in which adult animals have been attacked. Röll reports the disease in a cow eight years old. It is common during late summer and early autumn, although not limited to this period.

SYMPTOMS.

The disease symptoms are much alike in lambs and calves, both being due to mechanical obstruction of the smaller air-passages. They begin to appear in lambs and yearlings, when driven to pasture in spring and

fall, in the form of a severe bronchial catarrh. There is difficulty in breathing and a severe gasping, spasmodic cough. The cough gener ally comes on when the herd is driven to pasture. During the paroxysins, masses of mucus are occasionally discharged, with great effort, which contain eggs, embryos, and adult forms of the parasite. With increase in the intensity of these symptoms, emaciation goes on in spite of continued appetite. Anæmia appears characterized by a paleness of the skin and mucous membranes, the abdomen becomes enlarged, the eyes become dim; in sheep the wool comes away. Swelling may ap pear under the abdomen, at the joints, and under the jaws. Death from general debility finally terminates the gradual loss of vital powers. Sometimes the general plugging up of the smaller bronchi may bring about suffocation during a paroxysm of coughing. The disease in lambs, which is apt to be more severe in fall, may disappear in the spring in milder cases. A French observer reports in an outbreak in calves the presence of a painful cough, coming on in veritable paroxysms, far more violent than in simple bronchitis, and frequently leading to suffocation. Respiration is increased in frequency, the conjunctiva injected, the head extended on the neck, the mouth opened widely, and the tongue protruded to obtain air. The discharges from nose and mouth contain parasites.

The disease may last from two to four months and the prognosis is usually bad. Cases of suspected verminous bronchitis which die within a few days after the first appearance of symptoms ought to arouse suspicion and direct attention to a careful examination of the lungs and body generally immediately after death.

The above brief description of symptoms evidently refers to severe cases. The intensity of the disease is proportional to the number of parasities which have found lodgment in the lungs. In this disease, therefore, all grades of severity may be met with and many of the symptoms above enumerated may be entirely absent.

DIAGNOSIS.

In connection with a careful examination of the symptoms it is of importance to examine with a lens, or the naked eye if a lens be not at hand, the mucus discharged from nose and mouth. The adult worms will appear as small, white, interlaced filaments, like shreds of lint or white hair. Placed in tepid water, these often execute vermicular movements. The adult forms, especially the females crowded with eggs, appear like masses of coarse, white linen thread.

POST MORTEM APPEARANCES.

In an examination of the body of lambs and calves which have suc cumbed to the disease there will be found, besides absence of fat, effusion of serum into the pericardial, thoracic, and peritoneal cavities, the usual concomitant of great debility. The lungs are pale red, often nodular and adherent to the chest-wall. In places the lung tissue is solidified and sinks in water. The mucous membrane of the bronchi is inflamed and thickened in patches; sometimes there are blood extravasations and ulcerations. The bronchi are often enlarged or saccular. The parasites themselves are found in the trachea and bronchi, often rolled up into masses which occupy the recesses or sacs above mentioned, or plug up completely the smaller divisions of the bronchi. In the larger divisions

elevations or swellings are sometimes met with made up of nests of strongyli.

In the case of a cow which had suffered for months, and finally died from suffocation, Anacker, quoted by Zürn (Die Schmarotzer, &c., p. 274), describes the lungs as follows:

Bronchi filled with bundles of worms enveloped in a viscid, bloody mucus. The mucous membrane presented the appearance of a catarrhal inflammation. It was much reddened and studded with hemorrhagic points and patches. Lungs œdematous. Much serum flowed on cutting into them. Some lobules were inflated aud slightly inflamed. Most were hepatized or solidified and surrounded by strips of tissue infiltrated with serum, so that they represented small oblong fields in which the alveoli, filled with pus, were recognizable as small gray nodules projecting slightly above the cut surface. The thorax and pericardium contained much serum,

Several calves affected with lung-worms were received at the experimental station October 21. One of them was killed for examination October 26. During its stay at the station there were no marked indications of pulmonary disease, excepting a cough, which slowly decreased in severity. There was no discharge from the nose, no difficulty in breathing. Physical examination revealed local loss of resonance and increased crepitation.

The lungs (Plates VIII, IX) had a normal appearance with the exception of some irregular patches of a dark red color, more numerous posteriorly where the pleura was also much clouded. On removing them from the thorax no adhesions could be detected. The posterior half of both lungs, however, was found doughy, not fully collapsed. Large masses of hepatized tissue were wedged in and bounded by normal tissue. The solidified portions were of a deep-red flesh color, with paler points scattered through it, representing the finest bronchioles. This tissue sank immediately when placed in water. There was no hypertrophy of the interlobular connective tissue. On slitting open the smaller bronchi bun'dles of adult worms were seen, almost filling up the lumen of the tubes. The worms were arranged parallel with one another, a few projecting from the opening of each smaller bronchus into the larger tube. (Plate IX, Fig. 2.) The mucous membrane of these tubes was pale and.covered with a very slight amount of mucus.

Portions of the lung were placed in the refrigerator over night and examined on the following day, when the cut ends of the bronchi were found crowded with worms partly extruded. It was thought that the absence of respiration induced an outward migration of the worms and might explain the crowed condition of the larger bronchi. Of all the worms examined the caudal extremity was turned towards the trachea, however.

Scrapings from the mucous membrane of the bronchi and from the cut surface of the hepatized regions contained ova and active embryos. The embryos within the ova moved at intervals, proving that they were nearly prepared to leave the shell. The bronchi containing the parasites were quite uniformly surrounded with hepatized tissue. The bronchi penetrating healthy lobes were found empty.

In the disease of lambs recently minutely described by A. Koch (loc. cit.) the surface of the lungs is studded with ten to thirty yellowish uodular elevations varying from the size of a lentil to that of a walnut and elastic to the touch. Smaller nodules about the size of a hemp-seed usually accompany the others, but are situated near the borders of the lungs. On section these nodules are observed to represent modified aircells filled with a milky fluid, and containing small, hair-like, interlacing, filamentous worms scarcely distinguishable with the naked eye. Under