234 PNEUMOMYCOSIS 



Some sections show a widespread interstitial and alveolar 

 hemorrhage, the blood showing a considerable increase in the 

 number of leucocj'tes. The capillaries are congested and areas 

 of oedema with thickening of the alveolar walls are not un- 

 common. 



There is peribronchitis and arthritis, while in some sec- 

 tions arterial thrombosis is seen, the thrombus being penetrated 

 b}' mycelium, though no fruit is found. Areas are also found in 

 which the alveoli are filled with a cellular exudate producing 

 consolidation and thickening of the alveolar walls. 



Emphysema, both interstitial and vesicular, is marked 

 and often extreme. Around the borders of the interstitial 

 cavities is a distinct zone made up of red blood cells, leucocytes 

 and hemogeneous material, which is yellowish both in fresh as 

 well as in stained sections. These areas contain very little 

 mycelium. All sections show a small amount of anthracosis. 

 The appearance of sections varies in different nodules as they 

 are taken further and further away from the center. In 

 general the fungus is thickest at the center, so thick in many 

 instances that the lung tissue is hidden entirely and grows 

 less as we go outwards. The tissue changes noted, take place 

 in a zone bej^ond 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 low amplification. 

 This form is considered to show a marked reaction and resist- 

 ance on the part of the animal and a lowered vitality in the 

 fungus. When found it indicates that the aspergillosis is a 

 primary and not a secondar}' 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 epi- 

 thelium 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. Wherever the formation of fruit was 



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