278 BACTERIA IN RELATION TO PLANT DISEASES. 
o{ the blade. The leaf was now cut away close to the stem with a hot knife. There were no si 
until after August 5. On August 8 (eight days after the removal of the pricked leaf) the blade of the 
first leaf up hung flabby and the one below had wholly shriveled. The next three up showed a slight 
droop. Five days later several more leaves were drooping. 
(368.) This plant was 20.5 inches high. The sixth leaf was inoculated, 6.5 inches from the 
stem. Its blade was 5.5 inches broad. Atg a.m. of the fourth day there were no signs, but at 2 
p.m. there was a wilted area extending from the pricked part toward the tip of the leaf, affecting 
about 2sq.cm. At 5 p.m. the wilt was decided, involving all of the pricked area and a narrow strip 
extending nearly to the apex of the leaf (about 2 cm.). The pricked leaf was now cut away at the base. 
This plant was examined July 27 and 31, August 8, 13, 17, 19, 28, and at later dates. None of the 
other leaves became affected. On September 23 the plant was still living and free from this disease. 
(369.) This plant was 16 inches high. The fifth leaf was pricked 9 inches from the stem. The 
pricked leaf-blade was 6 inches broad. The fifth day at 10 a.m. the leaf was still normal in appear- 
ance but 3 hours later there was a slight wilt in and around the pricked area. By 3 p.m. the wilt had 
spread rapidly. It then covered about 8 or 9 sq. cm. and reached nearly half-way down the blade. 
I now removed the leaf at the base using a hot knife. (This leaf was saved in alcohol for sections.) 
There were no signs until after July 27. Ten days after the removal of the pricked leaf (July 31) the 
blades of the first two leaves above were drooping badly. The first leaf below was normal. Five days 
later several more leaves above the pricked one were wilted. The eighteenth day after the removal 
of the pricked leaf additional leaves near the top of the vine were wilting. 
(370.) This plant was 19 inches high. The fifth leaf was inoculated 7.75 inches from the stem. 
The pricked leaf-blade was 6 inches broad. The fifth day, at 10 a.m. there were no signs but at 3 p.m. 
there was wilt of about 0.5 sq. cm., in the center of the pricked area. The wilt increased very little 
over night but the seventh day at noon it covered about 5 sq.cm. around the pricks. The eighth day 
was cool with heavy rains in the afternoon and the wilt was at a standstill. The following day, 
however, was sunny, transpiration was greater, and the wilt of the pricked leaf, at 2 p.m. covered 
about 12 sq. cm. and reached nearly half-way to the base of the blade. I now cut the leaf away at 
the stem with a hot knife. None of the other leaves contracted the disease. 
(371.) This plant was 20 inches high. The fifth leaf was inoculated 9.5 inches from the stem. 
The pricked leaf-blade was 5.5 inches broad. There were no signs up to noon of July 23. The ninth 
day (July 25, 2 p.m.) there was wilt of about 3 sq. cm. in and around the pricks. Two days later 
(10 a.m.) the pricked area was dead but there had been only a slight increase of wilt. The following 
afternoon (July 28, 5 p.m.) the leaf was cut away close to the stem with a hot knife. At that time 
there were about 8 sq. cm. of wilted tissue in the vicinity of the pricks. There were no constitutional 
signs until after July 31. On August 8 (11 daysafter the removal of the pricked leaf) the first leaf below 
was shriveled and the blades of the second below and first above drooped a little. The sixteenth day 
after the removal of the pricked leaf there was bad wilt of several additional leaves above the inocu- 
lated one. I now cut off three leaves and examined them. On touching the cut ends with my finger 
the bacteria in the vessels strung out 1 to 2 cm. in numerous fine, sticky, cobwebby threads. 
(372.) This plant was 22 inches high. The fifth leaf was inoculated 9.5 inches from the stem. 
The pricked leaf-blade was 6 inches broad. Up to the fifth day at 3 p.m. no signs had appeared, but 
the morning of the sixth day about 1 sq.cm. of tissue in the pricked area was wilted. By noon of the 
following day the wilted area was about fifteen times as large and reached half-way to the base of the 
blade. The leaf was now cut off at its junction with the stem, using a hot knife. None of the other 
leaves contracted the disease. On September 23 (69 days) the plant was still living and free from 
the disease. 
(373.) This plant was 23 inches high and very thrifty. The sixth leaf was selected for inoculation. 
Its blade was 5 inches broad, and the pricks were made 8 inches from the stem. On the seventh day 
at noon there was about 1 sq. cm. of wilt in the outer part of the pricked area. During the next 2 
days the wilted area increased not more than 1 sq.cm. The eleventh day, at 10 a.m., the pricked 
area was dead and the surrounding tissue yellow, but there was only a slight increase of the wilt. 
Four days later (July 31, 2 p.m.) there were about 25 sq. cm. of wilt, reaching three-fourths of the way 
to the base of the blade. With a hot knife the leaf was now cut away at its junction with the stem. 
There were no constitutional signs until after August 5. Eight days after the removal of this leaf 
the blade of the first leaf up was drooping decidedly and the blades of the next two above showed 
a faint wilt (August 8, 10a.m.). I now cut away the petiole of the first leaf up at its base, using a 
hot knife and examined it by tetiching the cut end with my finger. The surface ooze was sticky and 
strung a little. During the next 5 days several additional leaves wilted. 
(374.) This plant was 22 inches high. It was inoculated on the fifth leaf 10.5 inches from the 
stem. The pricked leaf-blade was 6 inches broad. Up to the fifth day at 10 a.m. there were no 
signs, but 3 hours later there was a slight wilt, and at 3 p.m. there was a decided wilt involving about 
