WILT OF CUCURBITS. 283 



were no signs on any of the plants until after July 30. The Mexican plant is Dr. Edward 

 Palmer's No. 1801a, and was grown from seeds of his collecting. 



(430.) Cucumber. Up to August 2 (seventh day) there was no result from the inoculation. 



(431.) Cucumber. The fifth day there was a distinct wilt of several square centimeters around 

 the pricks on each leaf. 



(432.) Cucumber. The fifth day there was a distinct wilt of one square centimeter in the pricked 

 area on one leaf while the whole blade of the other leaf was wilted and collapsing. 



(433.) Cucumber. The fifth day there were several square centimeters of wilt in the pricked 

 area on both leaves. 



(434.) Cucurbitaceous plant (collected in Mexico). No result by the sixth day. No further 

 record. 



(435.) Duplicate of 434. The sixth day both leaves were normal. No further record. 



Remarks. Three out of the four cucumbers contracted the disease promptly. The 

 ill-scented Mexican plant bore yellow flowers; long, warty fruits, and leaves suggestive 

 of Momordica. 



Inoculations of August 21, 1897. 



A series of inoculations was made on watermelon vines (Citrullits vulgaris) in a garden 

 atHubbardston, Michigan. The bacteria were taken from a potato-culture of B.tracheiphilus 

 (tube 2, July 23) which had been re-inoculated July 26 with 0.2 cc. out of tube 1, July 19. 

 This potato-culture was very sticky and in fine condition on August 12 when it was exhibited 

 at the Detroit meeting of the American Association for the Advancement of Science, but at 

 the time of the inoculations it had been considerably exposed to the light and was past its 

 prime, although I believed it to be alive. It was not, however, tested under the microscope 

 or by transfer to other media as it would have been had I had laboratory facilities. The 

 inoculations were made in the ordinary way, i. c, by means of a dozen or two needle-punc- 

 tures on the leaf-blade and within an area of 2 or 3 sq. cm. The extreme upper part of the 

 potato bore the stickiest slime and this was used for most of the inoculations, but some were 

 made in the following way: Numerous punctures were made and then the tube was tilted 

 until the cotton plug was wetted. This plug was then taken and mopped over the pricked 

 area. The fluid in the bottom of this tube was very milky. The inoculations were made at 

 sunset so as to avoid the immediate evil effect of light. As a check on the virulence of the 

 culture eight muskmelon leaves belonging to five plants were inoculated in the same way. 

 On four leaves the bacteria were pricked in; on the others they were mopped in after the 

 pricks were made. 



(436-439.) Watermelons. Sixteen healthy leaves belonging to four vines were inoculated, 

 eight in the ordinary way, four by the second method described. 



There was no result. 



(440-444.) Muskmelons. Eight leaves belonging to five plants were inoculated, four by the 

 second method. 



The inoculations failed. 



Remarks. The observations were continued until September 12. The weather was 

 very dry. Probably the potato culture was dead. It will be remembered that it was 26 

 days old and that it had been very copiously inoculated on the start. 



Inoculations of July ii, 1898. 



A series of inoculations was made on the wild bur cucumber (Sicyos angulatus) growing 

 in a garden at Anacostia, D. C. The plants were large and covered the ground, the leaves 

 being 4 to 8 inches broad, and all were perfectly healthy. All of the inoculations were made 

 by pricking in the bacteria (cucumber-strain) with a sharp steel needle. 



(445-456.) About a dozen leaves belonging to several different plants were inoculated in the 

 blades from a pure agar-culture (tube 3, June 30, re-inoculated July 7.) The seventh day there were 

 seven beautifully typical cases in as many of the pricked leaves. These were in all stages from one 

 just beginning to change color and wilt around the punctures to one wholly collapsed. There was 



