96 VEGETABLE PARASITES. 



birds. Nevertheless it is unusual to find any other 

 signs of disease in fowls suffering from Mvcosis. 



Mode of Infection. 



The spores set free from other Aspergilli enter 

 with the air the respiratory passages. Finding heat 

 and moisture two conditions most favourable to 

 fungoid development, they rapidly germinate on the 

 moist warm mucous membrane. As the mycelium 

 advances, inflammation is set up. 



Forms of Aspergilli. 



Four species of ' Moulds ' seem to be parasitic 

 namely, A. glaucus, Link, A. ?iiger, Yan Tieg. 

 A.fumigatus, Fresenius, and A. candidus, Link. 



Effect of Temperature. 



The temperature of the body has much to do with 

 the development of these mould-spores. A. glaucus, 

 for instance, will not germinate at the animal tem- 

 perature, and thus cannot do any harm except 

 mechanically, the spores alone being able to obstruct 

 the small air-passages, if in large numbers. A. niger 

 will only grow at 95° F., and thus cannot flourish in 

 Birds *. A. fumigatus, which seems to require a 

 temperature of 98° to 104° F. to develop, has been 

 shown by Schiitz to be by far the most dangerous 

 parasite of the fowl. 



* The average temperature of a bird is 103° to 104° F. 



