H. WORMALD 219 



The failure to obtain definite positive results in the majority of the 

 plants was probably largely due to the persistent dry weather which 

 obtained at the time the plants were under observation ; in the case of 

 parsley however all the inoculated leaves collapsed in less than 48 hours. 



In another series of experiments plants were taken into the labora- 

 tory and placed under bell-jars after inoculation, thus maintaining 

 a moist atmosphere ; under these conditions they proved to be generally 

 less resistant. In those cases where the plants were small enough two 

 of each kind were placed under the same bell-jar, one for inoculation 

 the other to act as control ; the control plants were punctured with a 

 sterile needle. The results were as follows:— 



Turnip. All the inoculated leaves collapsed within 48 hours after 

 treatment. Within a fortnight the crown of the plant was destroyed 

 so that even those leaves which had not been inoculated were attacked 

 at the base and also collapsed. The control plant though grown under 

 the same bell-jar remained quite healthy (Plate I^ fig. 3). 



Inoculations made on the root of a young turnip growing under 

 a bell-jar led to a gradual development of the rot ; after 5 days it had 

 extended from 0-15 to 0-75 cm. from the punctures. A control plant 

 showed no evideace of rot. 



Swede. Rot extended a few millimetres from the points of inocu- 

 lation, then further development . appeared to be inhibited and the 

 leaves remained upright. 



Lettuce. Inoculations made on lettuce plants on three separate 

 occasions invariably gave negative results, the only difference that 

 could be observed between the inoculated and the control leaves was 

 that after 24 hours the former showed a dark rim round each puncture, 

 the control wounds remaining colourless. Fourteen leaves were 

 inoculated in all but no rot could be detected in any one of them in 

 spite of the fact that in the third experiment a plant with young tender 

 leaves was specially selected for inoculation. 



Radish. Four leaves inoculated on the midrib all showed dis- 

 coloration round the wounds after 24 hours and two of the leaves 

 collapsed within 48 hours. 



Parsley. Of three leaves treated two collapsed within 24 hours 

 and later the third followed. At the end of a week the rot had extended 

 to the base of the youngest leaf inoculated. 



Carrot. All the inoculated leaves collapsed within 24 hours and 

 by the fifth day had become quite withered. A control plant under 

 the same bell- jar remained healthy. 



Journ. of Agric. Sci. vm 15 



