MOLD OR HYPHOMYCETE GROUP 



403 



ported only from this one locality, but in this instance affected 

 several thousand horses on the Umatilla Indian reservation. 



Morphology. The mycelium upon culture-media is septate and 

 branched. Three forms of spores are produced. The microconidia 

 are small and oval, one- or two-celled. The macroconidia are 

 large, sickle-shaped, three to five septate, and pointed at the 

 ends. They are 25 to 55 U long by 2.5 to 4.5 u wide. Chlamydo- 

 spores are formed in the mycelial threads, by a cell rounding up to 



Fig. 179. Fusarium equinum, mycelium and conidia (Melvin and Mohler, 

 Bureau of Animal Industry). 



a diameter of 8 to 15 fi and becoming densely granular. The 

 spores may be recognized in the hair-follicles of the diseased ani- 

 mals. 



Isolation and Culture. Xo difficulty was experienced in secur- 

 ing a growth of the organism on artificial media. The more 

 favorable media are potato and bread, but good growth will take 

 place on glucose or plain agar. The growth is white and cottony, 

 and the spores are produced in abundance. 



Pathogenesis. Inoculation experiments were unsuccessful, so 



