398 VETERINARY BACTERIOLOGY 



Character of Disease and Lesions Produced. By far the greatest 

 number of cases of aspergillosis have been reported from birds. 

 The lesions are generally located in the lungs, air-sacs, and hollow 

 bones, where the spores may readily lodge. In man and animals, 

 particularly the horse, the usual picture is an infection of the lungs 

 and air-passages, but occasionally of the mucous membranes of 

 other parts of the body. Metastatic infection of other organs is 

 not infrequent. The organism causes the development of nodules 

 not unlike those of tuberculosis. In the lungs the tubes are fre- 

 quently occluded by the green fructifications of the fungus. There 

 is more or less necrosis of tissue immediately surrounding the or- 

 ganisms. 



Immunity. Several investigators claim to have produced toxic 

 substances, if not true toxins, by the growth of the organisms in 

 artificial media. These claims have not been sufficiently sub- 

 stantiated, although there is considerable a priori evidence, 

 from the character of the lesions and symptoms, that powerful 

 toxic substances of some kind are produced. No method of suc- 

 cessful immunization has been developed. 



Bacteriological Diagnosis. A diagnosis may usually be made 

 by the character of the lesions and the appearance of the green 

 spores. A microscopic examination of the scrapings of the in- 

 fected mucous membranes should reveal the spores and character- 

 istic conidiophores without difficulty. 



Transmission. The organism doubtless grows on decaying 

 organic matter outside the body. The feeding of moldy grain or 

 fodder may give ample opportunity for infection by inhalation. 

 The preponderance of pulmonary primary infections shows that 

 inhalation probably is the common method of infection. 



Aspergillus flavus 



This organism has been described by various investigators, 

 who believed it to be, in part at least, responsible for blind staggers 

 or meningoencephalitis in horses. It occurs in great quantities 

 on moldy corn and other grains. Although the complete data 

 have not been presented, the work of Haslam indicates that it is 

 of some pathogenic significance. 



Morphology. The sterile hyphae are cobwebby and white. 



