Fusariitni in Tuber Rot and Wilt of Potato 7 



new species (F. trichothecioides Wr.). They refer to it as " a wound 

 parasite capable of destroying potato tubers" and say "this disease 

 is clearly differentiated from the wilt and dry rot ascribed by Smith 

 and Swingle to F. oxysporum." 



Later, the writer (19) submitted his studies of a dry rot occurring 

 among Nebraska potatoes as a thesis to the Graduate Faculty of 

 the University of Nebraska. The work was done at the request 

 of Dr. E. Mead Wilcox, and consisted in part of a study of the mor- 

 phology of a Fusarium that had been isolated from dry rotted tubers 

 in 1908 by Miss Venus W. Pool from potatoes that farmers had 

 sent in from throughout the state during the season 1907-1908. 

 Miss Pool established the causal relation of this Fusarium to the 

 dry rot by experimental infection, and' named the organism in 

 manuscript F. pulverulentum, because of its powdery habit of 

 growth. Both held and laboratory work were carried on for 

 several years, and it was found that this organism caused primarily 

 a dry rot of the tuber, and that it was not the F. oxysporum of Smith 

 and Swingle, a culture of F. oxysporum having been furnished 

 the laboratory for comparative work through the courtesy of 

 Dr. Smith. The results were to have been published in 191 1, and 

 the organism was to be named F. pulverulentum, but upon the ap- 

 pearance of Appel and Wollenweber's monograph Dr. Wilcox 

 proposed to the writer that he reinvestigate the organism along 

 the lines suggested by these authors. This was especially desirable 

 since F. oxysporum had been dropped and several new species estab- 

 lished. Not only was this carried out, but the whole etiology was 

 gone over again and all of Miss Pool's results verified. It was 

 found that Appel and Wollenweber (5) had not described the 

 species, and consequently it was described as F. tuberivorum 

 Wilcox and Link (40). It was so named because of the apparent 

 restriction of its activity to tubers. 



A comparison of this paper and the paper of Jamieson and 

 Wollenweber (16) made it seem quite likely that both were deal- 

 ing with the same organism. The organism was isolated in the 

 Washington laboratories from potatoes sent in from Washington, 

 Nebraska, and other states in 1910, and Wollenweber upon his 

 arrival in the laboratory, using his monograph as the basis, described 



