E. J. Welsford 45 



Ritzema Bos found eelworms in some plants of Narcissus Tazefta 

 which he had planted in soil infested with the eelworra of barley, but 

 he states that bulb growers in Holland find that Narcissus bulbs do 

 not sufEer from bulb rot. He says (iii. p. 230) " J'appris aussi par des 

 cultivateurs de bulbes a fleurs de Haarlem, que les tulipes, les lis, la 

 couronne imperiale et les narcisses ne sont jamais atteints de la maladie 

 causee par les anguillules (maladie annulaire)." 



Thus in 1887 it is clear that the eelworm disease of Narcissus was 

 little known in Holland though it was then very prevalent among 

 Hyacinths. 



The occurrence of eelworm disease in Narcissus is mentioned by 

 Marcinoswski(8) in 1910 but no account is given of it and it seems 

 reasonable to conclude that though it was recognised in Holland in 

 1910 it was comparatively rare. 



Hewitt (4A), working in Ireland, seems to be the only other investi- 

 gator who has described the occurrence of Ttjlenchus devastatrix in 

 Narcissus bulbs. His paper is short and deals mainly Avith the action 

 on the bulb and organism of various "steeps." In the light of our 

 present knowledge it is clear that he was dealing with "bulb rot"; 

 but his description of the diseased condition is so brief that apart from 

 the nature of the infecting organism the nature of the disease he 

 describes would remain uncertain. 



The account given here of the cause and progress of the bulb rot 

 of Narcissus shows that certain precautionary measures will check to 

 some extent the ravages of the eelworm. Such measures may briefly 

 be summarised as follows: 



(1) Narcissus should not be planted in ground previously infected 

 with TylenclvKS devastatrix ; the danger is especially great if the eelworms 

 have been liberated from a previous crop of Narcissus. 



(2) Care should be taken to plant healthy bulbs only ; one diseased 

 bulb will soon infect many others. 



(3) When a bulb does not produce foliage at the proper time it 

 should be dug up and burnt before it rots and liberates eelworms in 

 the soil. 



(4) Bulbs with "crinkly" or very curved leaves should be burnt. 



(5) Dying leaves should be gathered and burnt before they can 

 fall on the soil and so possibly infect it. 



(6) Weeds growing in infected soil should be pulled up, put directly 

 into baskets, and burnt. 



