STUDIES OF DISEASE PRODUCING SPECIES OF FUSARIUM. 235 



growth. Red color appeared at the center of the plates in 3 to 

 5 days and a little later the whole of each plate showed deep 

 red, when viewed from the under side, except for a little yellow 

 in F I. In the plates of F II and F IV the small amount of 

 white aerial growth produced large numbers of spores of the 

 obovate type. When these spores were sown in other plates 

 of prune agar the young colonies first produced long, septate 

 spores and later, on the aerial growth, large numbers of 

 obovate spores developed. 



F III from apple developed no aerial mycelium on this 

 medium. When the cultures were 3 weeks old many spores 

 were being formed. These were aggregated in a number of 

 little masses surrounding the center of each plate. The large 

 hyphse showed some yellow color. 



All of the fungi from various sources which have been 

 described as producing obovate spores agreed quite closely with 

 what has been described for the similar strains from apples. 

 Some of these did not produce as large a proportion of septate 

 spores as the strains from apple but all did produce septate 

 spores in young colonies when the obovate spores were sown 

 in plates of prune agar. This has been observed so frequently 

 in forms from different sources as to give evidence that the 

 development of the difi^erent types of spore depends to a large 

 extent on the conditions of growth. 



F. putrefaciens, F XII, differed very much in its appearance 

 on this medium from the other apple fungi. No red color devel- 

 oped but instead many of the large hyphse showed a deep yellow 

 color. 



The Fusarium from wheat, F VIII, which has been referred 

 to as giving a growth identical with that of Fusarium I and 

 other strains from apple gave further evidence of this relation 

 when grown on this medium as the growth was very similar. 



F. roseuni, F XVIII, made a rather rapid growth so that 3 

 days after the transfers were made the colonies were 2.5 cm. in 

 diameter. At that time the central part of each colony was deep 

 red, the color extending out a little more than one-half of the 

 distance from the center to the edge of the growth. At the end 

 of one week, the mycelium covered the entire surface of each 

 plate and showed a deep red color identical with that in the 



