FusARiA OF Potatoes 99 



servative basis from those species. These organisms were then designated 

 as new varieties of the following old species: 



Fusarium caudatum Wr. (one new variety) 



F. culmorum (W. Smith) Sacc. (one new variety) 



F. discolor Ap. et Wr. (one new variety) 



F. falcatum Ap. et Wr. (one new variety) 



F. Martii Ap. et Wr. (two new varieties) 



F. metacroum Ap. et Wr. (one new variety) 



F. oxysporum Schlecht. (three new varieties) 



F. redolens Wr. (one new variety) 



F. Solani (Mart. p. par.) Ap. et Wr. (two new varieties) 



F. subulatum Ap. et Wr. (one new variety) 



F. udum (Berk.) Wr. (one new variety) 



The remaining organisms of the genus Fusarium were then named as 

 new species and their varieties. It is probable that at least some of them 

 have been previously described, but the descriptions given are so incom- 

 plete that any reasonable identification is doubtful. The matter of identi- 

 fication is discussed on another page. 



Besides the Fusaria, several organisms were isolated in the course of 

 the work which more or less closely resemble Fusarium though belonging 

 to a different genus (Ramularia) of the Hyphomycetes. As these organ- 

 isms are often found on the potato and are easily confused with species 

 of Fusarium, they are treated here, but of course under their proper generic 

 name. 



On the whole the work, with a few exceptions, fully verifies the princi- 

 ples laid down by Appel and Wollenweber (1910). The chief exceptions 

 are as follows: (1) The Fusaria as such can be distinguished on almost 

 any medium, including artificial media, provided that the medium is not 

 extremely poor or rich in food materials and also provided that the moisture 

 supply in the medium is well regulated. (2) The microconidia should 

 be recognized as a special kind of spores because of their importance in 

 classification of these fungi. Though microconidia genetically do not 

 represent a separate kind of spores, nevertheless their typical absence 

 for certain closely related Fusaria, as well as their typical presence for 

 others, is characteristic. Besides, whenever they are present they have 

 a constant and often distinctive type of their own. (3) No typical core- 



