STUDIES OF DISEASE PRODUCING SPECIES OF FUSARIUM. 237 



tures gave a normal development of spores. The conclusion is 

 that the use of sugar -broths has no value in the classification 

 of these fungi. 



Growth in Fermentation Tubes. 



Ail of the 24 strains which were used in the other culture 

 work were grown in fermentation tubes. Each fungus was 

 grown in two tubes for each medium and the following media 

 were used : one per cent dextrose, saccharose, lactose and man- 

 nite broths, and 5 per cent glycerin broth. None of the fungi 

 grew in the closed end of the fermentation tube in any of these 

 broths and none produced gas so the fermentation tube proved 

 to be of no diagnostic value. 



Relation of Growth to Alkaei and Acids. 



One per cent dextrose broth was used as the basis for the 

 media in testing the efifects of different strengths of alkali and 

 acids upon the growth of strains from 24 sources. It was found 

 that all of these fungi made good growth even when large 

 amounts of NaOH were added to neutral dextrose broth. At 

 — 60 of Fuller's scale only a little difference could be noted 

 when the tubes were compared with cultures of the same age 

 growing in the neutral broth. When larger amounts of NaOH 

 were added, the growth was less so that at — 100 a distinct 

 difference could be noted in the amount of growth as compared 

 with the check cultures. There was a small amount of growth 

 in all of the tubes at — 150 NaOH fcut no growth took place 

 when the medium was made — 200 of Fuller's scale. Not 

 enough difference in the growth of the different forms in rela- 

 tion to the alkalinity of the medium could be observed to be of 

 value in the separation of species. 



In determining the amount of acid which prevents the growth 

 of Fusarium, the acids used were hydrochloric, sulphuric, nitric, 

 lactic, oxalic, and formic. Normal solutions of these acids were 

 prepared and these were added to neutral one per cent dextrose 

 broth in suiffcient quantity to make the medium of the desired 

 acidity. The same fungi which were used in the other culture 

 work were grown in the media which were the same except for 

 the amount and kind of acid which had been added. Two tubes 



