272 BACTERIA IN RELATION TO PLANT DISEASES. 
petiole being still rigid. ‘Two days later the plant was very sick, all of the leaves, seven in number, 
having wilted. The eleventh day the stem was still green and turgid. July 14 the plant was entirely 
dry-shriveled as a result of the inoculation. 
(295.) Cucurbita foetidissima (Toumey’s first sending to Mr. Hicks). ‘The sixth day (3 p.m.) 
there was no sign of the disease but 23 hours later the leaf on the pricked side had changed to a dull 
green and was wilted over an area of about 10 sq. cm. from the pricks outward, up, down, and inward 
to the midrib. The rest of the plant was uninjured. The ninth day the whole of the pricked leaf 
had shriveled except the petiole which was turgid. For distribution of the bacteria in the petiole 
of such a leaf see fig. 77, and for a detail from the same see fig. 78. The wilt now also showed on the 
blades of three other leaves—the first 
down and the first two up. ‘Two days 
later all but one leaf was wilted, the 
stem, however, was still turgid and 
green. On July 14 the plant was dry- 
shriveled, with the exception of the 
base of the stem which was green. 
(296.) A podanthera undulata (From 
Toumey, Tucson, Arizona). The 
pricked leaf was examined frequently 
but there was no marked result from 
the inoculation. On July 14 the plant 
was healthy. Part of the pricked area 
had dried out and most of the leaf- 
blade which was pricked was yellowish 
and yellow-green, but it had never 
shown any tendency to wilt. 
(297.) Apodanthera undulata. ‘The 
seventh day all the foliage was slowly 
drying out but not as a result of the 
inoculation. ‘Two days later there was 
a slight wilt (3x4 mm.) in the center 
of the pricked part. This portion later 
became dried out and brown but the 
plant did not contract the disease and 
on July 14 the rest of the pricked leaf 
was normal. 
(298.) A podanthera undulata. Plant 
examined June 23, 25, 27, and July 3. 
‘There was no result from the inoculation. 
Up to July 14 the pricked leaf had not 
wilted and the plant was healthy. 
(299.) Cucurbita palmata? (Seeds 
received from Toumey: Said to have 
been collected in California). Up to 
July 14 there had been no wilt and the 
plant was growing rapidly. 
(300.) Cucurbita palmata (?). On 
June 25 the plant was normal. The 
: eleventh day the pricked blade was yellow 
Fig. 77.* and shriveling, but 28 days after the inoc- 
ulation there was still no general wilt. 
(301.) Cucurbita palmata (?). Up to June 27 the pricked leaf showed no signs. On July 14 the 
pricked leaf-blade had wilted and some of those above it were yellow, but it was doubtful whether 
this was due to the disease because there was a fine growth of healthy vine beyond the pricked leaf 
and no good leaves below it. 
(302.) Cucurbita digitata (From Toumey. The plant identified as Cucurbita californica looks 
and tastes something like this). The seventh day there were tiny dead spots in the pricked area 
*Fic. 77.—Cross-section of leaf-stalk of Cucurbita foetidissima, the wild gourd of the western plains of the United 
States, showing vascular system occupied by Bacillus tracheiphilus. Plant grown in a hothouse in Washington from 
seeds obtained in Arizona. Inoculation from a pure culture by means of needle-pricks in blade of leaf. Petiole fixed 
in strong alcohol, infiltrated in paraffin, sectioned on microtome, stained in carbol-fuchsin, and differentiated in 50 
per cent alcohol. Drawn from section with aid of Abbe camera. Slide 254 D1. 
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