26o BACTERIA IN RELATION TO PLANT DISEASES. 



the stunted terminal growth which developed in the weeks immediately following the inoculations. 

 The leaves were larger and of a good green and this portion of the plant was blossoming. March 4 

 the terminal 18 inches was dead. There were some good green leaves and the vine was still blossom- 

 ing. It grew about 3 feet after inoculation. 



(219.) Winter Squash var. Pikes Peak. This vine resisted admirably although the leaf received 

 nearly 100 pricks. Twenty-three days after inoculation the leaf was yellow-green around the pricks 

 and slightly flabby but there was no well-defined wilt. November 11 (37 days after inoculation) the 

 blade of the pricked leaf and of the one next below were somewhat yellow-green but neither was flabby 

 and there were no other signs. November 29 the vine was blossoming freely but was stunted and 

 yellowish and losing leaves toward the base. December 3 the stem was 1 2 inches long and had 1 1 

 leaves. The basal leaf had shriveled nearly to the stem and the blade of the next up was yellow and 

 shriveling. The stem and the foliage were light green. The foliage was dwarfed but the vine was 

 blossoming profusely. This small plant had already borne 5 big blossoms (staminate). March 4 

 the vine was still in blossom. It had about 50 leaves, two-thirds of which were pale yellowish but not 

 wilted. The rest were green. 



(220.) Winter Squash var. Pike's Peak. The ninth day the pricked leaf -blade had changed color 

 and wilted around two of the largest groups of pricks, while 24 hours later at least one-third of the 

 pricked leaf drooped and nearly all of that part had become a lighter green. The wilted area on the 

 opposite side of the leaf-blade (spot No. 2) had not sensibly increased. The following day wilt spot 

 No. 2 had extended a little. There was no other change. Twenty-four hours later this side of the 

 pricked blade drooped also and one of the cotyledons which had its origin at almost the same level as 

 this leaf was beginning to droop. The petiole of the pricked leaf was still rigid. On October_2i, the 

 part which was wilted 4 days before was yellow and shriveling and hung down. The petiole and basal 

 part of the blade were still green and turgid. A week later the pricked leaf-blade was brown and 

 shriveled at the edges but green in the middle part and erect. There were no constitutional signs. 

 November 1 1 the pricked leaf was yellowish-green in the middle of the blade. The petiole was stiU 

 turgid. The blade of the next leaf up was yellow and shriveling at the tip. November 29 this vine 

 resembled the preceding. December 3 it had 14 leaves and the stem was about 16 inches long. All 

 except the basal leaves were dwarfed. Two of the latter had shriveled with the exception of the base 

 of the petioles. It was blooming freely. The lower leaves were pale green. December 31 this vine 

 resembled 219. March 4 the vine was still alive but stunted. It was branched and had some good 

 leaves. 



Remarks. — There was no sudden wilt of any of these squashes. A memorandum of 

 October 14, states that "most of the squashes are taking the disease" but the final outcome 

 shows that they proved very resistant in comparison with the cucumbers and muskmelons. 

 Up to October 28, only two showed constitutional signs and in these the signs progressed 

 slowly. Indeed on October 24, five of the six squashes appeared as if they were going to 

 overcome the disease. This experiment indicates that the gherkin is also subject to the 

 disease. In the inoculated squashes there was a tendency to profuse branching and blossom- 

 ing. The same thing has been observed in the field (see p. 217). In general, infections are 

 more certain when made from young pure cultures than when made with slime taken 

 directly from the plant. On No. 220, the infections first appeared in the parts most severely 

 injured, i. e., where many needle pricks were made close together. Possibly to start the 

 disease in squashes a larger initial injury is necessary than in case of cucumbers or musk- 

 melons. Probably also, to be very sensitive, squashes must be growing rapidly and these were 

 growing slowly. Query: Are the tissues more acid in slow-growing than in rapid-growing 

 leaves? or more acid in squash than in cucumber? These hypotheses were formulated at 

 the time as a partial explanation of the failures previously recorded. The squashes were 

 planted in 6-inch pots in good soil. Query: Is the squash-disease due to an organism 

 slightly different from the cucumber-organism? 



Inocui,ations of November 16, 1895. 



Three vines, a muskmelon, a cucumber and a squash, were inoculated at 4 p. m., 

 with a white bacillus taken directly from the interior of a diseased cucumber-fruit grown in 

 Barnabas Bryan's hothouse at Anacostia, D. C, and brought in to me for determination 

 on November 14. The bundles of this fruit contained a very sticky stringy bacillus, great 



