284 ASPERGILLOSIS 
Some sections showed a widespread interstitial and alveolar hemorrhage, the blood 
showing a considerable increase in the number of leucocytes. The capillaries were 
congested and areas of edema with thickening of the alveolar walls were not uncom- 
mon. 
There were peribronchitis and arteritis, while in some sections arterial thrombosis 
was seen, the thrombus being penetrated by mycelium, though no fruit was found. 
Areas were also found in which the alveoli were filled with a cellular exudate producing 
consolidation and thickening of the alveolar walls. 
Emphysema, both interstitial and vesicular, were marked and often extreme. Around 
the borders of the interstitial cavities was a distinct zone made up of red blood cells, 
leucocytes and homogeneous material, which was yellowish in fresh as well as stained 
sections. These areas contained very little mycelium. All sections showed a small 
amount of anthracosis. The appearance of sections varied in different nodules as they 
were taken further and further away from the center. In general the fungus was 
thickest at the center, so thick in many instances that the lung tissue was hidden 
entirely, and grew less as we went outward. The tissue changes noted took place in 
a zone beyond the greatest growth of the fungus. In other nodules the fungus was 
evenly distributed throughout, following the alveolar walls. In these the- tissue 
changes were slight. At times the fungus grew in dense, brush-like clusters, closely 
resembling actinomycosis under low amplification. 
This form was considered to show a marked reaction and resistance on the part 
of the animal and a lowered vitality in the fungus. When found it indicated that the 
aspergillosis was 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 found in sections, in spaces the nature of 
which it was impossible to determine accurately. Whenever 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 center of the nodules, the mass of 
mycelium was so dense that the structure of the tissues was obscured. Besides the 
dense growths resembling actinomycosis already described, other brush-like clusters 
not unlike them were frequently seen. These differ from the former in being somewhat 
less compact, and that from their periphery numerous hyphae run out into the sur- 
rounding tissues, whereas in the actinomycotic form the masses are sharply defined 
and only here and there a few threads grow out beyond the clusters. 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. 
Diagnosis. Pulmonary aspergillosis in cattle is diagnosed by find- 
ing the fungus in the tissues or the detection of the fungus in the 
discharges. The symptoms suggest those of pulmonary tuberculosis. 
There is thus far no specific reaction for detecting the presence of this 
infection. The course of the disease is chronic. 
