[Vor. 3 
40 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
of importance also. The medium upon which the culture is 
grown and the state of the mycelium and spores have been 
pointed out by Wollenweber as important factors in other 
species of Fusarium which produce plant disease, and doubt- 
less they bear their part in the irregularity of the results 
presented here. 
In a series of inoculation experiments made at the Missouri 
Botanical Garden, recently isolated cultures were used as 
sources of infection. The cultures were grown on cooked po- 
tato stems, and inoculation was effected by placing a bit of 
the culture tissue in contact with a wound on the hypocotyl 
of the plant. The plants were in the cotyledonous stage, and 
after inoculation were placed in normal uninfected greenhouse 
soil. Five seedlings were placed in each pot. Table rv gives 
the results of the experiments. 
TABLE IV 
PRELIMINARY STUDY OF VARIATION OF VIRULENCE OF FUSARIUM 
CONGLUTINANS IN PURE CULTURE 
No. of Per cent of 
Culture Total no. diseased diseased 
number isolation of plants 
BN E 7/14/13 40 30 75.0 
те 11/17/14 15 13 86.6 
он. 2/1/15 5 5 100.0 
EE РУТИНЫ И 10 0. 
It will be noted that where the larger number of plants was 
used the percentage of infection fell. This result might have 
been expected if the age of the cultures used and the great 
variation in susceptibility of the host plant were taken into 
consideration, but to gather more data on these points a trial 
was made with a large series of cultures that had been isolated 
at various times and also from various sources. 
Table v gives the data on the inoculation experiment which 
was carried out similarly to the one just reported. 
