31 



variety, and in the same pot, were iield for comparison. The interior 

 of eight to ten flowers on each plant was thoronghly infected by forci- 

 bly spurting- 0.2 cc. of cloudy alkaline beef broth (from tube 3, February 

 10) into the throat of the perianth. Great care was taken not to spill 

 any of the culture on the leaves or to wound the flowers with the tip of 

 the needle. The pot was wet down thoroughly, covered with a bell jar, 

 and shaded from the light. After twenty-three hours the bell jar was 

 removed, the interior of the injected flowers being still moist. The 

 plants were in full bloom and very thrifty. 



Result. — On March 2 one scape showed a trace of water-soak in the 

 part occupied by the flowers, but there were no additional subsequent 

 symptoms. On June 21 these bulbs were dug and examined. Neither 

 one showed any trace of the yellow disease. The two check bulbs 

 were also sound. This variety took the disease slowly in series 7. 



SERIES 17 (HYACINTHS). 



This series was in all respects a duplicate of the preceding, except 

 that I used two single, blue-flowered specimens of Baron van Tuyll, 

 and inoculated a third jjlant in the leaves, holding two healthy plants 

 in the same pot as checks. On February 16 eight to ten flowers were 

 inoculated on each plant, each receiving 0.2 cc, which was spurted into 

 the depths of the perianth, where it remained in foam. Of the plant 

 inoculated through the leaves, one leaf received 0.4 cc. and the other 

 two leaves 0.2 cc. each. Each foliar inoculation was made well toward 

 the apex of the leaf. 



Result. — On March 2 one of the two plants inoculated in the flowers 

 showed distinct symptoms in the scape. These consisted of a water- 

 soaked stripe beginning in the middle part of the inflorescence in one 

 of the inoculated flowers. The stripe extended downward about 5 cm. 

 and involved about one-third of the circumference of the scape. In 

 the ujjper part of it the vascular bundles were feebly browned (PL I, 

 fig. 7). The disease moved downward rapidly in the scape, and on 

 Mar(;h 31 the soft white rot having set in, the bulb was dug and exam- 

 ined. There was some yellow slime in the plateau, and one bundle 

 of one scale was visibly invaded by the yellow microoraanism. The 

 part of the bulb recently invaded by the soft white rot was the upper 

 central part, i. e., that previously injured by the growth of the inocu- 

 lated organism. Up to March 31 the other i^lant developed no symp- 

 toms on the scape or leaves, but the bulb was wholly decayed when 

 dug and examined June 17. The cause of this decay was not then 

 (letei'mi liable. 



The plant inoculated through the leaves developed beautifully typ- 

 ical water-soaked stripes down the middle of each leaf. On M;irch 

 2, two of these stripes were over lo cm. long. On March 31 tlic inocu- 

 lated leaves were shriveled over halfway to tlie bulb. This plant 

 was not again examined until ,Iune 17, when the bulb was wholly 



