STUDIES OF DISEASE PRODUCING SPECIES OF FUSARIUM. 229 



rium, F VIII, isolated from wheat grown in Alaine, 2 strains, 

 F V and F VI, from ears of sweet corn collected in Maine and 

 another from yellow dent corn from Indiana, F XVII, one from 

 decaying winter squash, F XL, and one from summer squash, 

 F XXXI. This color usually appears in 3 to 7 days after the 

 transfers are made when the cultures are kept at room tem- 

 perature and exposed to the light from a North window. 



Species of Fusarium from the following sources have been 

 carried in culture on this medium for almost three years and 

 have always shown white mycelium : One species from cucum- 

 ber, F XIX; two strains from tomato, F XXI and F XXII, 

 probably one species ; one from .squash, F XXIII ; three differ- 

 ent isolations from diseased stems of China aster, F XIV, 

 F XLIV, F XLV, and one from decaying potato, F XXXIV 

 A species from stored potato, F XXXIII, and one from cucum- 

 ber, F XX, have produced blue color. 



Beet Cylinders. This medium was favorable to the growth 

 of all the species of Fusarium which were tested upon it. In 

 general the growth on beet is very similar to that on potato 

 with possibly a little more red color in those species which pro- 

 duce it. 



F I from apple nearly covered the slants after 4 days growth. 

 One tube showed bright red color at the surface of the liquid 

 and extending up along the glass where the cylinder was in 

 contact with the wall of the tube. There was also some 

 red color over the surface of the slant. The other tube did not 

 show quite so much but there was some mixture of red and 

 yellow. One week later there was little difference in the appear- 

 ance of the 2 tubes. When the cultures were one month old 

 septate spores were found which measured 4 x 25 to 41 microns. 



In the tubes of F II from apple the white aerial mycelium 

 almost hilled the space between the slant and the wall of the 

 tube and extended 8 mm. above the top of each slant at the end 

 of four days. Red color showed at this time on the surface of 

 the medium and was especially bright where the cylinder was 

 in contact with the wall of the tube. The amount of aerial 

 mycelium was greater with this fungus than with F I. One 

 week later the red color was becoming dull and some yellow had 

 appeared. There was a small amount of browning in "-he aer'al 



