MOLD OR HYPHOMYCETE GROUP 



401 



giving to the organism under the microscope the appearance of 

 being covered with little brooms. The sexual stage is essentially 

 similar to that of Aspergillus. Penicillia are even more common 

 than the Aspergilli. They occur as blue or green molds upon fruit, 

 and upon a great variety of decaying materials. Of the hundreds 

 of species of Penicillium that have been described, the majority 



Fig. 177. Penicillium glaucum: a, a 1 , Tips of conidiophores showing the 

 characteristic method of branching and the chains of spores; b, perithecium ; 

 c, asci; d, ascospores (Brefeld). 



are green or bluish-green in color, but white, gray, yellow, orange, 

 and brown forms are known. 



None of the species of Penicillium are known to be harmful, 

 but their constant presence in moldy silage and grain which has 

 poisoned animals makes it necessary to consider them in any 

 discussion of forage poisoning. 



THE GENUS FUSARIUM 



The members of this genus are nearly all saprophytes or plant 

 parasites. Fusarium is included among the Fungi imperfecti, 

 as a sexual or perfect stage is unknown in the life history of most 

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