238 MAINE AGRICUIvTURAI, EXPERIMI:nT STATION. I913. 



were used for each fungus with each strength of a given acid. 

 The amount of an acid which prevented the growth of one of the 

 fungi had the same effect on the others except for the strains, 

 F VII, F XV and F XVI, which grew in media which contained 

 sufficient acid to prevent the growth of the others. 



HA'drochloric, nitric, and sulphuric acids were unfavorable to 

 the growth of all the forms when added in sufficient quantity to 

 make the broth -|- 20 of Fuller's scale. At -)- 40 the growth 

 was very much checked and at -\- 50 there was no growth. With 

 lactic acid, there was a small amount of growth up to + 100 

 of Fuller's scale but above -{- 60 the strains of F. o.vysporum 

 showed better growth than the others. Oxalic acid checked the 

 growth at -|- 40 and there was very little growth of any strains- 

 except those of the F. oxysporum type at -]- 60. At -|- 80 no 

 other forms showed growth. With formic acid all of the tubes 

 showed a small amount of growth at -)- 20, at -|- 30 there was 

 very little growth and no growth in any at -{- 40. 



Grov^th in Relation to Temperature;. 



There was very little growth of any of the 24 forms, F I 

 to F XXIV, when transferred to potato cylinders and kept at a 

 temperature of 5° C, or below. At 15° C. there was good 

 growth but not so much as at 20° to 25° C. When cultures were 

 placed in the incubator at a temperature of 30° C. the growth was 

 not so rapid as at 20° to 25° C. At 33° C. it was less than at 

 30°, and those forms which produce a bright red color at lower 

 temperatures showed a rather dull red and in a part of the 

 forms yellow instead of red. At 37° C. none of the strains 

 showed growth at the end of one week but when after that time 

 the cultures were removed from the incubator and kept at room 

 temperature most of the fungi made good growth. 



Growth from Old Cultures. 



Growth from old cultures has been reported for a number 

 of species of Fusarium. By making transfers from time to time 

 it was found that cultures of the species isolated from apples 

 in Maine and also of F. putrefaciens, F XII, on bean pods, apple 

 wood, and potato cylinders were alive after a period of 18 



