same nodule as they are taken further and further away from the centre. In general the fungus is thickest at the centre, so thick in many instances that the lung-tissue is hidden entirely, and grows less as we go outward. The tissue changes

noted, formation of fibrin, etc., take place in a zone beyond the greatest growth of the fungus. In other nodules the fungus is evenly distributed throughout, following the alveolar walls. In these the tissue changes are slight. At times the

fungus grows in dense brush-like clusters, closely resembling actinomycosis under a low magnification. (See Fig. 3.) This form is considered to show a marked reaction and resistance on the part of the animal, and a lowered vitality in the fungus.

A section through nodule in lung, showing brush-like forms and mycelium in cross section. Stained by Lithium carmine and Weigert's fibrin method. X 150.

When found it indicates that the aspergillosis is a primary and not a secondary or terminal affection. No giant cells were found in any section.

Fruit formation was not observed in the substance of the tissues at any time. It was observed most frequently in

bronchi, which were for the most part denuded of their epithelium, and next in emphysematous cavities, where it could be detected in clusters by the naked eye. Fruit was also found in sections, in spaces the nature of which it was impossible to determine accurately. Wherever the formation of fruit was seen there were innumerable free spores as well as those still attached to the sterigmata, but in no case were spores detected in the substance of the tissues.

In many sections, especially those from near the centre of the nodules, the mass of mycelium was so dense that the proper structure of the tissues was obscured. Besides the dense growths resembling actinomycosis, already described, other brush-like clusters, not unlike them, were frequently seen. (See Fig. 4.) These differ from the former in being somewhat less compact and in the fact that from their periphery numerous hyphæ run out into the surrounding tissues, whereas in the actinomycoctic form the masses are sharply defined, and only here and there a few threads grow out beyond the cluster. Their appearance suggests that they may be actinomycotic forms which have finally overcome the resistance of the tissues. Emphysema is less marked in the neighborhood of the latter. These differences are well brought out in the photomicrographs. When a cluster is obliquely cut we have a mass of closely-set cut-ends of mycelium in cross section as seen in the left lower corner of Fig. 4.

The cow was examined carefully for the lesions of tuberculosis, and in one lung some four or five caseous and calcareous nodules 1 centimetre in diameter were found in which the tubercle bacillus was demonstrated, but no mycelium could be detected. In no part of the lung was there coexistence of the two infections.

The fact that the animal did not react to tuberculin, though tuberculosis was present, is noteworthy and suggests that the mould infection may interfere with the test-a source of error to be guarded against.

We have reported this case at some length as being of unusual interest. We have been unable to find any record of a similar one ever having been observed in America, the literature on the subject in this country being limited to two cases in birds, and one case reported by Osler to this society in 1887, in which mycelium was found in the sputum of a woman suffering from bronchial asthma.

We consider the case one of primary aspergillosis for the following reasons:

1. The aspergillar nodules were by far the most extensive lesions found, and amply sufficient to account for the symptoms and death.

2. No other lesions were found which could have caused the symptoms, the tuberculous nodules being few in number and confined to a small portion of one lung. They were also evidently not progressive.

3. The actinomycotic forms of the aspergillus were found in a number of the nodules, indicating strong resistance on the part of the tissues.

In conclusion, we wish to express our thanks to Dr. C. Y. White, of the Pepper Clinical Laboratory, for assistance in the histological examination of the nodules, and to Mr. Wm. H. Walmsley for his beautiful photomicrographs.

We have used freely the article on "Pulmonary Aspergillosis" by Rolleston, in Allbutt's System of Medicine, the monograph of Saxer, and especially the most admirable work of Rénon, to the authors of which we make grateful acknowledgments.

THE RELATION OF TUBERCULOSIS IN DOMESTICATED ANIMALS AND MAN.1

BY SOFUS B. NELSON, D.V.M.,

PROFESSOR OF VETERINARY SCIENCE, WASHINGTON AGRICULTURAL COLLEGE AND SCHOOL OF SCIENCE.

SINCE Koch, in 1882, demonstrated the bacillus tuberculosis to be the specific cause of tuberculosis, this disease has been a source of constant study. Without doubt it is one of the most important diseases with which man has to contend. Judging from the number of scientists that are laboring to unravel some one of the many phases of tuberculosis, of interest to the welfare of mankind, to which Koch's discovery was the first key, this importance seems to be indeed realized. Nearly all animals are susceptible to this disease. Among our domestic animals the cow, horse, sheep, pig, dog, cat, and chicken succumb to it. It has been observed in wild animals, such as the lion, tiger, bear, giraffe, monkey, etc., that have been placed

1 Read before the Washington State Medical Society at Spokane, May 9th, 1900.

and kept in confinement in zoological gardens. That rodents, especially in densely populated districts, are seriously affected has been demonstrated.

That certain wild animals, when kept in close confinement, contract and succumb to tuberculosis is not very important to us except as a fact; but that our domestic animals-our dumb friends, our source of various foods and material for our comforts and luxuries-are subject to this disease is of great importance, and deserves careful and thorough consideration. Of all the domestic animals the cow is the most susceptible to tuberculosis. In the others it is not found nearly so frequently. It is quite a rare disease in swine, as the following statistical statement shows: At Augsburg, out of 30,922 swine slaughtered, only 3 were affected.

Considering the domestic animals from a standpoint of economic importance, because of their individual utility to man, the cow stands first in the list, as she has all the points possessed by the other animals, and some that they do not. Here, then, is the cow, the most serviceable animal to man, and at the same time the most susceptible to a certain contagious disease.

The associating together of these two facts would not deserve a moment's serious thought if the contagious disease, tuberculosis, which affects the cow was not transmissible to man, and vice versa.

Before discussing this phase of the question it may be advisable to see whether or not the disease is the same in the different lower animals. Investigators are unanimous that tuberculosis in the lower mammals is the same, i. e., that the bacillus tuberculosis is the bacterium that causes the disease. There has, however, been a great deal of discussion over the question whether the bacillus that causes avian and mammalian tuberculosis is identical. Rivolta, Maffuci, Strauss, and others have held that they were not identical, either in morphology or pathogenesis, since the bacillus of avian tuberculosis will grow at 43° C., while that of mammalian will not. Also that it is very rarely that tuberculosis of mammals is transmitted to chickens. Finally, that certain mammals, as the dog and guinea-pig are not susceptible to the avian form. These arguments have been met by Nocard and other, in that the tuberculosis produced by the two bacilli were identical in clinical and post-mortem appearances. Numerous experiments have