BUNT, OE STINKING SMUT, OF WHEAT. 
17 
Reference to Table 13 shows that spores maintained at a tempera- 
ture of 1.4° C.j when properly aerated, germinated profusely after a 
lapse of 24 days, while the germination ox wheat, marked by emer- 
gence of the plumule, occurred on the tenth day of incubation. 
Primary conidia were produced in abundance, and the cultures were 
maintained until the seedlings were 
millimeters long. 
SERIES IX 
A B 
SERIES X 
yj^\ ^ 7^ 
Fig. 3.— Location and thickness of strata of bunt-infested soil in an 
experiment to determine the possible relation to infection of the dis- 
tance between seed and stratum of smutted soil. (Vertical scale, 
each space= one-fourth of an inch.) 
That the spores of Tilletia tritici are able to retain their viability 
under the adverse conditions of alternate freezing and thawing was 
demonstrated by allowing a water decoction of spores in a watch 
glass to freeze solid every night for more than a fortnight. Before 
the twentieth day there was profuse germination. 
Table 13. — Relation of temperature to germination of bunt spores of Jones Fife 
wheat, as shown by incubator experiments conducted at intervals during 1918 
and 1914- 
Incubator. 
Temper- 
ature, 
average 
for 18 
days 
Spore response. 
Wheat kernel response. 
day 
(°C 
No.l 1.4 
No.2 ! 4.9 
No. 3 1 8.6 
No. 4 j 13.4 
No. 5 1 19.0 
No. 7 ; 29.1 
First signs of germination on 25th day . 
Plumule 1 mm. Ions on 10th day; 7 
mm. long on 2.3th day. 
Plumules emerging on 4th day. 
Plumules emerging on 2d day. 
Do. 
Plumules emerging at beginning of 2d 
day. 
No response Plumules emerging on 1st day. 
First signs of germination on 12th day. 
First signs of germination on 5th d">y . . 
First signs of germination on ^th day. . 
First signs of germination on 2d day.. 
The optimum temperature for the germination of bunt spores 
according to results obtained with the compartment incubator lies 
between 18° and 20° C. Above that point, although there may be 
a fair degree of germination, it is difficult for the bunt organism to 
maintain itself against saprophytic molds which thrive at the higher 
