24 



from 0.5 to 0.7 co. of the cloucly alkaline beef broth culture (No. 4, 

 Jan. 20). 



Result. — Thirty-five bulbs had been planted in this box. Two were 

 rotted and gone when it was purchased, and a rapid soft rot devel- 

 oped on the scapes of two others a few days later, so that only thirty- 

 one healthy plants remained at the date of inoculation. The fifteen 

 plants held as checks never developed any leaf sj^mptoms comparable 

 to those on the inoculated plants, and fourteen of the bulbs were 

 entirely sound when dug and examined June 16. The other bulb was 

 free from the yellow disease, but was just beginning to succumb to 

 the soft white rot (the extreme top of the bulb). 



Every one of the fortj^-eight inoculated leaves (sixteen plants) 

 developed symptoms of the yellow disease. These symptoms 

 appeared for the most part only after fifteen to thirty days, and the 

 progress of the disease was xery slow, although distinctly visible for 

 a month or two, i. e., until the hot weather set in, when the disease 

 seemed to die out in many leaves. On June 16, when the bulbs were 

 dug and examined, two Avere soft-rotted, with the exception of a few 

 outer scales, which showed no trace of the yellow disease. The other 

 fourteen plants had better-preserved leaves than the corresponding 

 plants of Czar Peter (series 5). Ten of the bulbs were entirely free 

 from symptoms of the yellow disease and perfecth'^ sound so far as 

 could be determined by the unaided eye. The other four were 

 attacked by the yellow disease, but not extensively, and for the most 

 part only in those scales which bore the inoculated leaves. All of 

 this variety took the disease less rapidly than the Czar Peter. The 

 plants were very carefully examined from time to time and notes 

 made on the condition of each one, the two sets of notes which follow 

 being fairly illustrative of the whole lot. 



Notes on plant No. 4(9.— Inoculated February 7 in three leaves. 



February 14. No symptoms. The plant has five leaves which are now 17.5 cm. 

 high. 



March 1. One leaf only shows any decided symptoms. These consist of a stripe 

 in the upper central part of the leaf (the inoculated part) which is yellow in the 

 wider iipper part of the stripe and water-soaked in the lower 3 to 4 cm. The 

 length of the stripe is 9 cm., the breadth is 3 to 3 mm. in the upper part and only 

 1 mm. in the lower, water-soaked part. Symptoms in the other inoculated leaves 

 are restricted to the vicinity of the needle puncture, and consist of a slight water- 

 soaked appearance in the form of narrow, short, interrr.pted lines. All of this 

 white variety have taken the disease less rapidly than the Czar Peter. 



March 30. There has been a distinct progress of symptoms. On the first leaf 

 there is a stripe of yellow-brown, dry tissue 3 mm. wide and 7 cm. long. On the 

 second leaf there is a stripe 3 to 5 mm. wide and 3 cm. long, which is yellow with 

 a dry, brown center. On the third leaf the stripe is ~) mm. wide and 3 cm. long. 

 Most of this is simply yellow, but the central part is dry and brownish. Below 

 the well-defined stripe are narrow, short, interrupted water-soaked lines on a green 

 background. These water-soaked lines are separated from the older yellow- brown 

 stripeby 3 to 4 cm. of healthy-looking tissue. This appearance must be due to 

 germs which have broken out of the bundles and grown or diffused into the par- 



