WILT OF CUCURBITS. 263 



(229.) Common Gourd. This plant was like the preceding. With the exception of vine 227, all 

 the inoculations into Lagenaria failed to induce anything more than trivial local injuries. They were 

 inoculated for the third time on January 7 and numbered 260-262 (q.v.). 



(230.) Balsam apple. The tenth day there were no signs of the wilt, but 3 days later both pricked 

 leaves showed very small wilted areas. December 3 1 the pricked portions were dead and had narrow 

 yellow borders, but the rest of the leaf was normal, green, and turgid and there were no indications 

 of any secondary wilt. The plant was growing and had five times as much leaf-surface as when 

 pricked. The inoculation failed to induce anything more than local injuries and the vine was re- 

 inoculated January 7 and numbered 263 (q.v.). 



(231.) Balsam apple. Like the preceding. Re-inoculated and renumbered (264.) on January 7. 



(232.) Balsam apple. The seventh day there seemed to be a little wilt around some of the pricks 

 first made. The following day there was a plain case of wilt with change of color to a dull green on 

 the leaf-blade pricked December 3. About one-fourth of the outer part of the leaf had drooped. 

 The thirteenth day the wilt was increasing slowly on the first pricked leaf and a wilt-spot of a few 

 square millimeters had developed on the other pricked leaf (pricks of December 7). The twenty- 

 eighth day the inoculated leaf which had shown distinct wilt where pricked had dried out. Half of 

 this blade (the pricked part) was dead. The rest was a good green. The plant had grown well and 

 had five times as much leaf-surface as when pricked. It was re-inoculated January 7, and numbered 

 265 (q.v.). 



(233.) Cucumis angaria. The sixth day there were no signs but the following morning both the 

 pricked leaves and the one next above were badly wilted. The eighth day this vine had developed 

 a bad case of the bacterial wilt. The thirteenth day the plant, which was a small one, had collapsed. 



(234.) Cucumis angaria. The sixth day there was distinct wilt on the blade of the leaf first 

 pricked, also on the first leaf up and the first down (pricked December 7). It was 5! days since the 

 first inoculation. Two days later this plant was badly wilted and the thirteenth day it had collapsed. 



(235.) Luff a acutangula. The eighth day the plant was normal except for a little yellowing around 

 the groups of pricks made on December 3. The tenth day there were no signs of wilt. Three days 

 later both leaves were yellowish around the pricks but there was still no wilt. On December 31 (28 

 days after inoculation) the pricked areas were dead and had yellow borders but there had been no 

 wilt even of the pricked leaves. The vine had doubled its size since it was pricked. On January 7 

 it was re-inoculated and numbered 266 (q.v.). 



(236.) Cucurbita foetidissima. The sixth day the leaf inoculated on December 3 had wilted and 

 changed to a dull green where pricked so that the terminal third of the leaf-blade hung down flabby. 

 Twenty-five hours later the next leaf down (pricked December 7), was beginning to show a trace of 

 wilt. The following day the blade of the first leaf up and of the first below the pricked leaves drooped. 

 Thirteen days after inoculation (December 16) all the foliage had shriveled. The plant was a small 

 one. Two days later it was brought in and examined microscopically. Cross-sections of the stem 

 were not noticeably sticky but the interior of the vessels and surrounding parenchyma were gorged 

 with bacilli. At least one-tenth of the rods were noticeably larger than the rest. The largest were 

 estimated to be ten times larger than the smallest longer and broader. None were clearly motile. 

 Material saved in alcohol. 



(237.) Cucurbita foetidissima. The sixth day there were no signs of the disease but 2 days later 

 the blade of the leaf inoculated on December 3 snowed a trace of wilt at the apex where it was pricked 

 and also a slight change of color. The period of incubation was nearly 8 days. The following after- 

 noon the blade of the leaf first pricked was badly wilted. The next morning the blade of the second 

 pricked leaf was half wilted. Three days later (13 days after inoculation) all the foliage of this vine 

 which was a small one, was shriveled. The fifteenth day it was brought in and examined microscopi- 

 cally. The vessels and surrounding parenchyma were crowded with bacilli which were like those 

 found in the preceding. The cross-sections were not noticeably sticky. Material saved in alcohol. 



(238.) Cucurbita foetidissima. The sixth day the blade of the leaf which was first pricked had 

 changed to a light green and wilted in tiny spots around three of the four groups of pricks. Twenty- 

 five hours later the terminal half of the leaf first pricked had changed color and was drooping. The 

 following day the first leaf above and the first below were wilted, the petioles of the lower two leaves 

 being involved in the flaccidity. The thirteenth day the foliage had shriveled. The vine was a small 

 one. 



Remarks. Cucumis angnria and Cucurbita foetidissima contracted the disease promptly 

 and proved as sensitive as cucumber or muskmelon. Luffa, Momordica, and Lagenaria 

 were resistant. 



