STUDIES OF DISEASE PRODUCING SPECIES OF FUSARIUM. 233 



The fungi were grown both in Petri dishes which contained 

 10 c. c. of the medium and on slants in tubes which contained 

 5 c. c. The appearance of the growth of a number of the fungi 

 in Petri dishes is shown in Fig. 95 to 104. The development 

 of red color was held somewhat in check on this medium in 

 that it did not appear so early nor spread so rapidly as in the 

 growth on some other media. 



F I from apple spread rather rapidly, so that at the end of 

 one week the mycelium had reached almost to the edges of the 

 plates. The amount of aerial growth was less than in F II 

 from apple. Viewed from the under side there was 5ome yellow 

 color and some red, but 3 days later the red color had increased 

 so that one of the plates showed red over more than one-half of 

 the under surface. Large quantities of spores were produced 

 and when these w^ere examined on the tenth day they were 

 found to range from small one-celled to 5-septate spores 55 

 microns in length. 



F II from apple made a very rapid growth on synthetic agar. 

 At the end of one week the Petri dishes, which were almost 

 10 cm. in diameter, were filled with white aerial mycelium. 

 Viewed from the under side both cultures were slightly yellow- 

 ish and one showed some reddish color at the center. When 

 the cultures were 10 days old both obovate and septate spores 

 were found in large numbers. JMore than one-half of these 

 were septate. 



All of the strains with obovate spores from various sources 

 have been grown on this medium. They have all agreed in 

 the production of a large amount of white aerial mycelium 

 and in showing some red or yellow color on the under side. 

 The forms from apple and the one from sunflower have differed 

 fiom the others in the production of a larger proportion of 

 septate spores, but in other characters could not be distinguished 

 from the other strains. 



Ill the young cultures, F. putrefaciens, F XII, showed about 

 the same amount of white aerial mycelium as F I from apple. 

 When the cultures were one week old the mycelium took on a 

 yellow color. 



The Fusarium which was isolated from an apple which was 

 decaying on the tree, F XI, the one from wheat collected at 

 Orono, F VIII. and F I from apple made a very similar appear- 



