culosis. Mr. B.'s turkeys all died of tuberculosis. The turkey that is included in this shipment was secured from an adjoining ranch owned by Mr. R. Mr. R.'s chickens mix with the chickens of Mr. B., and a great many of them were tubercular and have been killed. His turkeys had all died except the one which I am forwarding.

Some of the affected livers from the tuberculous swine were obtained at the abattoir and were mailed to the laboratory at Washington, where attempts were made to study the character of the bacilli which caused the lesions. Owing to the distance that it was necessary to send these specimens the bacilli could only be studied as to their morphology after their arrival at the laboratory, as the material (formalin) in which they were packed made cultivation impossible.

The morphology presented by the tubercle bacilli from the hog specimens upon examination offers by no means a satisfactory basis upon which to support their classification. The form of tubercle. bacilli may be changed so quickly by alterations in their surroundings that we believe that no decision as to the type of any particular specimen of tubercle bacilli should ever be given until more extended observations have been made. Hence the experiments mentioned below, made by feeding these infected fowls to hogs and obtaining well-defined cases of hog tuberculosis, serve to complete the evidence which could not be obtained from the hog tissues forwarded.

FEEDING AND INOCULATION EXPERIMENTS.

There was not much in the general appearance of the fowls on their arrival at the laboratory to give one a suspicion that they were sick. They were all adult Plymouth Rocks, with evident good appetites, and they moved about in a strong, active manner. With two of them, however, it was noticed that their combs and wattles were not quite so bright as they should have been. These two birds were selected for the beginning of the test. They were killed and examined, and then, in order to make the experiment correspond as closely as possible with the conditions under which the disease had apparently been transmitted from fowls to hogs in Oregon, the viscera were at once fed to two young tuberculin-tested pigs between 2 and 3 months of age.

At the autopsy of hen No. 1 the spleen was found to be about three times its normal size and thickly covered with tuberculous nodules. The liver was thickly sown with small white foci, and tubercular foci were found in the lymph glands of the intestinal tract, but in this case no lesions were noted in the intestinal walls.

Hen No. 2, on examination, was found to have spreading tuberculous growths varying from 1 to 8 millimeters in diameter scattered about in the liver. These had the appearance of actively progressing

lesions. The spleen was about twice the normal size and thickly studded with tuberculous nodules. With this bird the infection was extensive along the intestinal tract, the intestinal walls supporting numerous tuberculous nodules from the size of millet seeds up to the size of beans. These growths appeared upon all parts of the intestines, except over some 8 inches of the posterior part. The nodules were quite firm in consistence, none of them showing any tendency toward pus formation.

In neither of the birds was there any affection of the lungs, ovaries, or oviducts.

The viscera from these two hens were fed to pigs Nos. 2399 and 2400 on October 14, 1908. On January 26, 1909, or one hundred and four days later, the animals were chloroformed and examined, when the following conditions were noted:

Pig No. 2399 was in prime condition. Section showed many small white tuberculous foci scattered about in the submaxillary glands, which were somewhat enlarged. No lesions were detected in the prescapular glands or in any organs of the thoracic cavity. On opening the abdominal cavity a large proportion of the mesenteric glands proved to be caseous, while the liver was found to contain numerous small white foci of tuberculosis and had become adherent to the abdominal walls by means of tuberculous growths over an area some 5 by 8 centimeters in diameter. Further examination with the microscope showed that the spleen also contained many tubercle bacilli collected in small groups, yet without forming visible necrotic centers.

The other pig, No. 2400, was also in excellent condition. Its submaxillary glands were greatly enlarged and contained many tuberculous foci, some of which were softening and breaking down. The mesenteric glands showed very general infection. Tubercle bacilli were found to be numerous in all the affected glands.

Here was the demonstration that was necessary to connect avian with porcine tuberculosis, and there seems to be no room for reasonable doubt that the condemned tuberculous hogs from the Oregon ranch owed their infection to the ingestion of the carcasses of the affected hens, just as the two hogs in the test at the laboratory contracted their infection unquestionably through feeding upon the two birds. It was, furthermore, a proof that danger to mammals may exist wherever tuberculous birds are present.

From the affected organs of the pigs cultures were obtained through feeding and inoculating chickens, rabbits, and guinea pigs, and then transferring the tuberculous tissues so obtained to artificial culture media. These cultures were found to conform to the avian type of tubercle bacilli in morphological and biological characteristics.

OCCURRENCE OF TUBERCLE BACILLI IN EGGS OF TUBERCULOUS HENS.

The two hens left of the original Oregon shipment were retained in the laboratory for several weeks after the first two had been used in feeding experiments. On January 6 an egg was found in their cage which seemed to be perfectly formed in every way. It was carefully opened aseptically at the larger end and numerous smears were made of its contents. No tubercle bacilli could be determined by these means, so recourse was had to guinea-pig inoculation. The syringe was carefully filled with white of the egg without disturbing the yolk, and two guinea pigs were at once inoculated intra-abdominally. Following this the process was repeated on other guinea pigs, using the yolk as material for injection.

Thirty-six days after these inoculations one of the guinea pigs that had received a portion of the white of the egg died. On examination a degenerated area some 5 by 20 mm. was found between the muscular layers of the abdominal walls. This area appeared inflamed and contained numerous small yellowish-white foci, in which, on microscopical examination, numerous tubercle bacilli were found. The spleen of this guinea pig was enlarged to fully three times its natural size and was considerably darkened in color. No tuberculous foci were visible in this organ, but the presence of tubercle bacilli was readily demonstrated by means of smears. The carcass of the guinea pig was in excellent condition, showing no emaciation.

The other guinea pig which received an inoculation with white of egg died on the forty-third day, and although no tuberculous foci were determined, the spleen and the mesenteric glands contained such numbers of tubercle bacilli as to produce well-marked lesions in guinea pigs subinoculated with them. From these lesions typical avian cultures were recovered upon egg media.

The guinea pigs receiving yolk inoculations failed to develop tuberculosis after observation for sixty-eight days, followed by autopsy.

On March 24 another egg was laid by one of the hens, but this egg was not quite normal in appearance and would at once attract the attention of the poultryman because of its diminutive size and because its contour formed a perfect oval, neither end being materially broader than the other. On opening this egg the yolk was found to be very small in size and of a pale yellowish-white color. As in the preceding instance, no tubercle bacilli could be demonstrated by microscopical examination, and 4 guinea pigs were at once inoculated with the white and the yolk separately. Fifty-eight days after inoculation these guinea pigs were chloroformed, when it was found that one of the two animals that had received inoculation with the white of the egg had developed evidence of tuberculosis. The spleen

contained a few small tuberculous nodules, while the liver, kidneys, pancreas, and mesenteric lymph glands showed the effects of the disease by swelling, congestion, and the presence of tubercle bacilli. The other guinea pig of this series was found to be perfectly normal.

The hen which laid the infected eggs was killed on April 13 and examined. She was in good condition, her tissues being well covered with fat. The abdominal cavity contained an excess of serous fluid. The liver supported several dense, hard nodules. The intestines showed numerous tuberculous nodules scattered about on the surface of their walls over the anterior portion of the intestine, or down to its juncture with the ceca. The mesentery presented over much of its surface an inflamed area thickly sown with small tuberculous nodules. The membrane of the oviduct was similarly inflamed for 2 inches or more above its opening at the vent, but here the nodules mentioned as present on the mesentery were lacking. The spleen contained many foci of tuberculosis, ranging in size from a mere point up to the dimensions of a millet seed. The kidneys were surrounded by delicate lines of tuberculous nodes, pinhead size, but the organs themselves were not affected. The lungs contained pronounced tuberculous lesions. In the left lung four foci were noticed that reached about 3 millimeters in diameter, while the right lung supported only one small node the size of a millet seed.

Smears were prepared from the various affected organs, especial attention being given to the oviduct, as it was fairly evident that the inflamed tuberculous surface of this organ must have been responsible for the infection of the egg with which we had been working, and the detection of tubercle bacilli by means of microscopic examination of scrapings from its surface confirmed this view. Tubercle bacilli were present in these scrapings in very small numbers, but from the readiness with which guinea pigs were infected by means of inoculation it seems probable that the eggs must have become quite thoroughly infected at some stage of development, probably during their intimate contact with the inflamed membrane of the oviduct. Cultures were readily obtained from the tissues of the guinea pigs which had become tuberculous through the egg inoculations. In every case the cultures grew in a manner characteristic of avian tubercle bacilli. From hen No. 3, the one just described as having a diseased oviduct, similar cultures were obtained directly upon glycerin agar without having recourse to animal passage.

RÉSUMÉ OF PREVIOUS INVESTIGATIONS.

Long before the discovery of the tubercle bacillus scientists had been interested in the study of tuberculosis in poultry but had been unable to determine definitely the real nature of the whitish nodules

which they had occasionally noticed upon the visceral organs of fowls. In 1882, however, Koch proved through the discovery of tubercle bacilli within these nodules that they were of tubercular origin.

During later years considerable study has been given to the question of the relation existing between avian and mammalian tubercle bacilli. Probably the most extensive article resulting from investigations of this nature is the report of Weber and Bofinger, of the Imperial Health Office of Germany, which appeared in 1904. These writers are very positive that fowls can not possibly be infected by mammalian tubercle bacilli, no matter how applied. They are equally positive that no transformation ever occurs, either of avian tubercle bacilli during a stay in the body of a mammal or of mammalian tubercle bacilli when supported by the tissues of a bird.

During their investigations they received a tuberculous pig which on examination proved to have been infected by avian tubercle bacilli. The cultures recovered from this pig assumed the manner of growth which is characteristic of tubercle bacilli of the avian type immediately on isolation, and continued to manifest these characters of growth through several subsequent generations. In the results which they obtained from the examination of this pig they fully substantiate findings reported by the present writers, for in both instances pigs were proven to have become tuberculous by natural. means of infection through contact with avian tubercle bacilli.

A report by Rabinowitsch, also issued in 1904, in which are recorded the findings of autopsies made upon 55 birds from the Berlin Zoological Gardens and the conclusions derived from careful study of cultures obtained from them, furnishes most valuable information regarding the relations of avian with mammalian tubercle bacilli. In two cases tubercle bacilli of the mammalian type were recovered from fishhawks. As other birds of the same species were found to be infected with avian tubercle bacilli, it seems justifiable to class fishhawks with parrots in the sense that both of these species of birds are susceptible to infection by either type of tubercle bacilli.

Rabinowitsch also succeeded in producing tuberculous lesions in two hens through feeding them with pure cultures of tubercle bacilli of human origin, but owing to the fact that no cultures were recovered from the bodies of the fowls afterwards some investigators are inclined to dispute the success of the experiment.

Important variations in the virulence of the various avian cultures were noted, a fact which has been fully substantiated by our work, and a condition which is quite in conformity with the variations found in cultures of other bacteria.