INVESTIGATIONS ON THE NARCISSUS DISEASE. 51 
INVESTIGATIONS ON THE NARCISSUS DISEASE. 
By J. K. Ramsbottom, Research Student. 
[Read before the Horticultural Club, May 8, 191 7.] 
Six months ago, when the Royal Horticultural Society asked me to 
read a paper on the Narcissus disease, I thought I might find myself 
in the position of Canning's knife-grinder who had no story to tell. 
I however fell in with the suggestion that I should give a resume of 
my investigations up to date. I was appointed in June last by the 
Royal Horticultural Society to investigate the disease of Narcissus 
commonly attributed to Fusarium, and but for the abandonment of 
the Daff odil Show my lecture would have been delivered before that 
Society. The Horticultural Club, on hearing of the abandonment of 
the Show, and knowing the keen interest taken in the Narcissus 
disease, invited me to deliver the lecture to its members. Hence my 
presence here to-night. 
On taking up my appointment a note was published in the 
leading horticultural papers inviting bulb growers to forward 
diseased specimens to Wisley. As a result of the splendid response 
of growers, hundreds of bulbs passed through my hands even during 
the first few weeks of the investigation, and thousands of slides were 
prepared. I was also given the opportunity of visiting a number 
of nurseries and bulb farms, and given practically a free hand on the 
approach of the lifting season. It is with much pleasure that I 
acknowledge the great assistance and exceptional courtesies I have 
received from many growers. 
When the investigation was commenced the disease was usually 
attributed to Fusarium bulbigenum, chiefly, no doubt, on account 
of the work of the late Mr. Massee, which was published first in the 
Kew Bulletin and then as a Board of Agriculture leaflet — but which 
was very incomplete. 
An investigation by Miss Welsford at the Imperial College of 
Science, which had been in progress for two years, was said to point 
to a fungal or bacterial origin of the disease. Special attention 
was therefore centred on the possibility of Fusarium being the cause 
of the malady ; but it was soon seen that this fungus was of remark- 
ably rare occurrence. When it was present it was always in associa- 
tion with a parasitic eelworm, and it was at first thought that there 
was possibly some connexion between the two organisms. As the work 
advanced, observations in the field and laboratory showed that the 
parasitic eelworm was the main factor to be considered. This eelworm 
agrees in ah respects with the descriptions of Tylenchus devastatrix, 
Kuhn. 
When the members of th§ Narcissus Committee of the R.H.S.visited 
