Fusarium in Tuber Rot and Wilt of Potato 



37 



sent the percentage of decrease in dry weight of material. The 

 last weighing in these cases unavoidably included the dry weight 

 of fungus material formed, so that the figures are higher than they 

 ought to be. The differences in weight in these cases give only com- 

 parative values of the amounts of material respired by the organ- 

 isms. The filter paper used was the best Swedish paper, and the 

 cork was obtained by skinning steamed potatoes, scrubbing the 

 skin thoroughly, boiling it for 48 hours in distilled water, extract- 

 ing for 48 hours in ether, and then boiling again with water. All 

 figures represent averages, the composition of these figures being 

 shown in tables VI and VII. In many cases there was a fair coin- 

 cidence of the values, while in others a great disparity appeared. 

 The averages probably would more nearly approximate the true 

 value if a greater number of figures were available. 



TABLE V 



Dry weight (in milligrams) formed in 6 and 12 days by Fusarium tricholhecioides 



and F. oxysporum 



