STUDIES OF DISEASE PRODUCING SPECIES OF FUSARIUM. 209 



Appel and Wollenweber " regard these as normal spores while 

 the spores of various shapes and sizes are regarded as abnormal. 

 They base much of their classification of species on the shape 

 and size of the spores produced in sporodochia. According to 

 their account the sporodochia are produced readily when fully 

 developed normal spores are transferred' to sterilized plant stems 

 in tubes. If on the other hand, mycelium is transferred there 

 is growth of much more mycelium and the sporodochia do not 

 develop so readily, if at all. The writer is able to confirm this 

 from the results of work with certain strains of this species 

 from apple. Sporodochia appeared in the cultures and when 

 transfers were made from these to potato cylinders the whole 

 slant became covered with an orange colored mass of spores, 

 after a few days' growth. On the same date transfers were 

 made using material from the aerial mycelium from the same 

 tube with the results that in the cultures from this source 

 mycelium began to develop at once giving a growth so dift'erent 

 in character from that which developed from spores that the 

 two sets of cultures might be classified as belonging to different 

 species or even genera if the classification was based on these 

 cultures alone without regard to their origin. 



F II from apple agrees in certain characteristics with F I. On 

 the same culture media the two fungi give a somewhat similar 

 appearance. Both produce an abundance of white aerial 

 mycelium although the amount is slightly greater in F II. The 

 red color is the same in the two forms and differs from that m 

 the cultures of F. putrefacieus, F XII. sent to me by Oster- 

 walder when all are grown on the same medium. In F. putre- 

 facieus the red color is not so bright but seems dull in compari- 

 son and it extends to the aerial mycelium to a greater extent than 

 in F I and F II so that there is not so much contrast between 

 the white aerial mycelium and the red color next to the medium. 

 This difference has been noted many times. 



F II can be readily distinguished from F I by microscopic 

 examination of the spores. In the former, an additional type 

 of spore is found. These spores are obovate to pyriform in shape, 

 the obovate spores usually being one-celled and pyriform spores 



* Appel, O., and Wollenweber, H. W. Grundlagen einer Monographie 

 der Gattung Fusarium (Link). Arbeiten aus der Kaiserlichen Anstalt 

 fiir Land-und Forstwirtschaft. Band VIII, Heft I, 1910. 



