Fiisarium 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. oxysporiim." 
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 \\^ilcox, and consisted in part of a study of the mor- 
phology of a Fiisarium that had been isolated from dry rotted tubers 
in 1908 by Miss Venus 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. pulvcndentiim, because of its powdery habit of 
growth. Both field and laboratory work wxre 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 1911, and 
the organism was to be named F. pulverulentum, but upon the ap- 
pearance of Appel and W^ollenweeer's monograph Dr. \\^ilcox 
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. tiibcrivorum 
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 
\\'ollen WEBER (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 A\'ashington, 
Nebraska, and other states in 1910, and Wollenweber upon his 
arrival in the laboratory, using his monograph as the basis, described 
