S. a. Paine 485 



that, on these alone, a separation into distinct species is not warranted. 

 These must therefore be considered as strains of one species to which 

 Morse applies, on grounds of priority, the name B. atrosepticus. 



COLLECTION OF THE MATERIAL. 



During the months of summer when "Blackleg" makes its appear- 

 ance the weather in 1916 was particularly dry over most parts of 

 England so there was perhaps less of this disease than is normally the 

 case. However when this investigation was begun in the second 

 week in August it was reported that there had been rather a considerable 

 amount of it in certain parts of Wiltshire and Devonshire and also in 

 parts of Surrey and Kent. The material investigated was collected 

 during a survey of Wart Disease in the Ormskirk District of Lancashire. 

 Stalks showing the symptoms of "Blackleg" were not numerous, in 

 fact on many fields they were difficult to find. This was mainly due 

 to the fact that the weather had been particularly dry for some weeks. 

 Several diseased stalks were pulled up here and there and cultures 

 were made the same night by inoculating from the most recently 

 diseased portions of the pith upon slopes of potato-mush-agar. On the 

 day of leaving the district a plot some twelve drills wide and of about 

 two acres area was found in which the percentage of " blacklegged " 

 stalks was very high, about one plant in six showing the disease. This 

 plot had no pegs or other marks to distinguish it from the neighbouring 

 plots but the appearance of "Blackleg" upon it was so marked that 

 its hmits could be most distinctly seen on looking down the drills. 

 Search was made on a neighbouring plot but not a single case of a 

 " blacklegged " shoot could be found. This was the more extraordinary 

 since the farmer gave the assurance that the seed was the same (King 

 Edward) and from the same source, that the manurial treatment had 

 been the same (namely a dressing of Fison's Mixed Artificial), moreover 

 the soil type appeared to be identical on the two plots. The only 

 difference lay in the setting of the "seed" ; in the one case use had been 

 made of a home-made dibbhng machine while in the other the drill 

 had been ploughed and the "seed" set in the ordinary way. In the 

 former case presumably the "seed" had been set nearer the surface 

 than in the latter and this would seem to have given rise to conditions 

 favourable to the action of bacteria. As this suggests a possible 

 method of control in bacterial diseases experiments will be made 

 during this summer in order to test the efficacy of deep planting in 



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