I 2 



present in quantities as great as t>% checked the growth of the 

 Fusarium it was thought that a determination of the relative acid in 

 green fruits would be valuable. Fruits of three sizes were selected 

 and tested, with results as below : 



ACIDITY OF JUICE IN TERMS OF MALIC ACID. 



Fruit Diameter. Amount of Acid.* 

 24 inch, 0.42$) 



i}( inch, °-S l $ 



2V2 inch, < 



The minimum size at which the fruit becomes infected is three- 

 fourths of an inch in diameter, while 2^ inches was the maximum 

 in these fruits before changing color. The acid, then, increases in 

 proportion as the fruit grows. We may certainly consider this as a 

 significant fact in explaining the arrest of the fungus. 



To ascertain the effect of any possible excretion of the mycelium 

 upon green tomato tissue, microscopic sections of the tomato were 

 treated with the mycelium extract. No immediate change took place 

 in the tissues. After about six hours, however, the cells were killed, 

 the protoplasm becoming slightly yellowed, shrunken and curled up 

 at the edges, and later the walls became blackened. 



The Fusarium was grown in Petri dishes on the following cooked 

 vegetables : Potato, carrot, beet, parsnip ; and corn in the form of 

 meal. The growth was quite uniform in all, though perhaps a little 

 more vigorous on potato than on carrot and corn, while that on beet 

 and parsnip was slightly retarded. In all cases the tissues were 

 blackened after becoming permeated by the fungus. The fungus is 

 doubtless the Fusarium so/am', Mart, of Galloway. 



OBSERVATIONS ON OUTDOOR TOMATO CROPS. 



During the summers of 1902 and 1903 some work was done by 

 the writer on outdoor tomato crops. Here there was no difficulty in 

 finding all of the fungi recorded by writers previously quoted. In 

 many cases the spot was entirely covered almost from the first with 

 a dense growth of Macrosporium so/aui, but almost as often the 



* These results were furnished by the department of Foods and Feeding of the Experi- 

 ment Station. 



