New York Agricultural Experiment Station. 521 



point to bacteria in the tissues ; bnt the microscope reveals neither 

 fungus mycelium nor bacteria in the stem or in the diseased spots 

 on the leaves. To determine this, a large number of cultures were 

 made of the aerial parts of diseased plants. Lily agar was used as 

 a culture medium. Cultures made from leaves and buds developed 

 various fungi and bacteria, but no one species appeared constantly. 

 Cultures made from the interior of stems of diseased plants either 

 developed nothing or only occasional colonies of fungi and bacteria 

 admitted by accident. From all this, it appears that the cause is 

 not to be found above ground. In an examination of the bulb, the 

 first objects to attract the obsei'ver's attention are certain circular, 

 depressed spots of brown color. These contain the mycelium of 

 some fungus which was not determined. They are not constantly 

 associated with the disease and probably have no connection with it. 

 Cultures made from the dead root tips developed numerous colonies 

 of two species of bacteria : First, A very large, motile, spore- 

 producing Bacillus. A single plant inoculated with this germ 

 showed no disease, and it was afterward ascertained that the Bacillus 

 is a common one in green-houses, on the roots of carnations, callas, 

 dracaenas and other plants, even where no lilies are grown ; Second, 

 A small, motile Bacillus. A quantity of this germ was grown in 

 sterilized lily juice and an inoculation experiment made. In Mr. 

 Dean's green-house four healthy plants were selected. On April 26 

 three of these plants were removed from their pots, and their white 

 young roots sprayed thoroughly with the lily juice containing the 

 Bacillus. The plants were then returned to the pots and a quantity 

 of the lily juice poured around the base of each plant. The fourth 

 plant was kept as a check. As late as June 5 none of the plants 

 showed any trace of the disease. Here the investigation was dis- 

 continued for the time beins^. 



Dr. Halstedi has reported a lily disease (probably the same) which 

 he thinks is du3, primarily, to a leaf-attacking f nngus belonging to 

 the genus PhylhMicta. He also found a species of Yerjnicularia 

 and mites, which he thinks may in some cases account for the loss 

 of vigor. I, too, found on the bulbs Yermicularia and mites, but 

 by no means constantly and seldom in sufficient numbers to account 

 for the damage. 



Some florists maintain^ that the disease is due to a loss of vigor 



1 New Jersey Agricultural Experiment Station Report, 1891, p. 3r2. 



2 See discussion in Florists' Exchange for 1895. 



