21 



rot. None of the remaining thirteen check plants contracted any 

 disease and their bulbs were sound and entirely free from yellow 

 bundles when cut open and examined on June 14. 



Two of the inoculated plants were also attacked by the same rapid 

 soft-rot. 1 The bulb of one, which was left undisturbed, finally 

 decayed completely; that of the other was pried out February 14 to 

 prevent the spread of the disease. At this time there were no foliar 

 symptoms due to the inoculations. The soft-rot had just begun. It 

 started at the base of two leaves in wounds accidentally made by the 

 knife of the gardener in cutting away the scape. 



Distinct sjanptoms of the j^ellow disease appeared on the above- 



' This parasite, which is a rapid-growing, bad-smelling, actively-motile white 

 germ, probably identical with Bacillus hyacinthi-septicus Heinz, came from the 

 hot house where the bulbs were forced. The box originally contained 35 bulbs, 

 the rotten. sour-sme!ling remains of 3 being discovered and pried out after its 

 purchase. All the plants inoculated in 1898 came from this same forcing house 

 and nearly every pot or box developed some cases of this disease. Otherwise the 

 plants were very satisfactory. 



This organism was not studied critically, for lack of time, but some notes were 

 made. The bacterial .slime and accompanying tissues of the host plant taken 

 from the upper inner part of a diseased scape (the advancing margin of the 

 decay) were examined microscopically. There was no mycelium or insect injury, 

 and the innumerable bacilli were apparently all one thing. The rods were 3 to 

 5 // long, and rather less than 1 /< broad, with rounded ends. They were single 

 or in pairs. Very few were in motion at first (the slime was diluted with a drop 

 of distilled water), but within a few minutes many became actively motile. 

 This motion consisted mostly of rapid movements straight ahead, and often 

 straight back in the same track, for a distance many times the length of the rod. 

 Tiambling and sinuous moveuients, however, were also observed. Toward the 

 close of the first hour at least one-fourth of the rods were in motion. In form, 

 the motile ones were exactly like the others. While watching, I frequently saw 

 stationary rods become motile and dart away. These rods stained readily in basic 

 fuchsin water and in gentian violet water. This slime from the host plant gave 

 a faint bad smell and was slightly sticky, stringing up 1 centimeter. Cultures 

 made directly into tubes of potato from the same part of this scape, after cutting 

 it open with a burning hot knife, yielded a rather slow-growing, not very copious, 

 wet-looking, smooth, white slime, which was strongly alkaline and somewhat 

 sticky, stringing up 1 to 3 centimeters when touched with the loop. The four 

 potato cultures were alike at first and three continued to be homogeneous, while 

 a pink organism appeared in the fourth tube at the end of the second day. A few 

 gas bubbles also appeared in each of the tubes. 



This particular hyat-inth plant was a robust Czar Peter in full bloom, with a 

 long stocky scape. The rapidity of the rot may be judged from the fact that 

 when the disease was first discovered it involved only one flower. In forty-eight 

 hours the scape was soft-rotten (and lopped over) from the point of infection 

 nearly to the balb (10 or 15 centimeters) and also 3 to 5 centimeters above the 

 point of entrance— i. e., to within a few centimeters of the top of the inflorescence. 

 It was a soft wet rot, involving all of the tissues in a general collai)se of slime 

 which was strongly all^aline. Another fact worthy of note is that this organism 

 is (piite tolerant of acids. 



That we have here a genuine* bacterial disease of the hyacinth, worthy of careful 

 study, admits of no doubt whatever. 



