292 
Journal of Agricultural Research 
Vol. VII, No. 6 
At intervals of about five days after the plants were well above the 
ground one or more plants were carefully removed from the soil with as 
much root system as possible. The soil was then washed off the roots, 
after which they were usually placed immediately in 80 per cent alcohol 
and transferred to the laboratory, where microscopical examination of any 
spots or lesions occurring on the roots were made. Where T . basicola was 
found without difficulty, three to five examinations only were made; 
but where it could not be found on reported or suspected hosts, the roots 
of io to 15 plants were carefully examined, except in a few rare instances 
where this number of plants could not be obtained. 
EXPERIMENTAL RESULTS 
The results obtained are presented largely in the following tables. The 
host plants are separated into those reported by earlier workers (Table I) 
and the new hosts (Table II). For convenience in reference the authority 
for the first report and the country and year in which reported are given. 
These columns are followed by the results obtained with the various 
plants in the present experiments, giving at the same time the approxi¬ 
mate degree of susceptibility, as nearly as could be determined by the 
amount of infection obtained. In the same way these results are given 
for the new hosts reported here. From Table I it may be seen that out of 
the 39 host plants previously reported the parasitism of T . basicola on 25 
of these has been corroborated. Of the remaining 14 species infection 
could not be obtained on 7 species. Seeds or plants of 7 species have 
not been secured up to this time, but infection in most of these cases was 
obtained upon closely related species, indicating at least that the unob¬ 
tainable species are for the most part probably susceptible to attack. 
Sixty-six new species of plants have been added to those already reported 
and corroborated as host plants of T . basicola . As will be seen from the 
list, these are largely in the leguminous, solanaceous, and cucurbitaceous 
families. Although the plants tested were largely representatives of these 
families, a number of species of other families have been included in the 
tests, especially species of the Compositae, Gramineae, and Rosaceae. It 
is fairly safe to conclude from these tests that the latter families are 
generally immune from attack by T . basicola . 
