150 MOULDS; FILAMENTOUS FUNGI; HYPHOMYCES. 



do not thrive in the body. The absence of oxygen and the 

 alkalinity of the tissues speedily prove fatal. 



Those that survive may become pathogenic by developing 

 excessively, and thus acting as a foreign body. Levy and 

 Klemperer say that there is no actual multiplication, but 

 simply a germination. The number of spores injected is also 

 of importance, as many disease foci are required to produce 

 actual disease. The animal dies as a result of the extension 

 of the foci of disease, and not from intoxication. Diseases 

 of the surface of the body due to the filamentous fungi are 

 common, but rarely prove fatal. 



Moulds are distributed widely in nature, and cultures of 

 all varieties are obtained readily. The principal moulds are 

 the following : 



Aspergillus or bulbous moulds (Fig. 59) : The sporangium 

 terminates in a club, which is surrounded and completely 



FIG. 59. 



Aspergillus. At b a few of the spore-bearing sterigmata are shown ; the usual 

 picture is given at a. (Mez.) 



covered by short, thick, flask-shaped structures radially 

 arranged. These are known as sterigmata, and on the ends 

 of them are found the conidia or spores. Aspergillus fumi- 

 gatus, Aspergillus glaucus, and Aspergillus niger are examples 

 of this class. The aspergillus moulds, especially Aspergillus 



