262 Blacl Currant Eelworm 



The final section of this experiment deals with an endeavour to 

 discover whether the worm causing bud rot in black currants could 

 be identified with the members of the group Anguillulidae causing 

 specific disease among plants. 



Special importance was attached in this case to the experiments 

 dealing with the infection of the strawberry as host. The necessity for 

 such work arose owing to the suggestion by the eelworm specialists 

 to whom the worm was sent for identification, that the nematode 

 was probably identical with Aphelenchus fragariae which causes the 

 disease known as "Cauliflower disease" on the strawberry. 



The laboratory work in this connection was carried out under the 

 same conditions and duration of time as that of the previous experi- 

 ments, but the experimental work in the orchard was continued over 

 a period of two years. 



It was unfortunate that it was not possible to obtain sterile seedlings 

 for these experiments. The nursery from which the plants were 

 obtained however was apparently free from the particular disease. 

 The so-called Cauliflower disease is a particularly obvious one and if 

 present it could hardly be overlooked among several houses of forcing 

 strawberries. Moreover the disease is a peculiarly local one and has 

 only been recorded from a few localities in England. 



As a precaution however, the plants to be used for the experiment 

 were kept under running water for several hours and repotted in sterile 

 pots and soil. 



The variety used was Royal Sovereign and one dozen well-grown 

 fruiting plants were chosen for each experiment. These plants were 

 kept as previously described under the conditions found to favour 

 migration, and soil inoculation was employed throughout. 



The results obtained from the plants thus treated were curiously 

 similar to those obtained in the previous experiment. Worms were 

 found to have established themselves in much the same proportion 

 between the young folded leaflets, especially in those plants kept under 

 conditions of excessive moisture. Cast skins only were likewise present 

 in many of the leaves. The hard white buds of the strawberry, the 

 leaves of which are closely appressed, were however in no case invaded. 

 Discoloured areas were present on those portions of the leaves on 

 which living worms were found and such evidence of decay was absent 

 in the control plants. 



None of the characteristic symptoms of Cauliflower disease appeared 

 however during the experiment, and plants kept for a period of two 



