Ethel M. Doidge 55 



Cohn's solution. No growth. 



Dunham's solution. The organism grows rapidly in this solution, 

 but the clouding is not dense ; there is no pellicle or rim and the deposit 

 is slight. 



Uschinsky's solution. Growth copious but not viscid. 



Biochemical and Physical Relations. 



Enzyme production: Amylase. Amylolytic activity is indicated by 

 the fact that the organism liquefies starch jelly. 



Gas. No gas is produced in fermentation tubes with glucose, 

 saccharose, lactose, glycerine, maltose or mannite. 



Pigment. None, organism is white or greyish white on all media. 



Imlol. A considerable amount of indol is produced. 



Acid and alkali production. Ordinary nutrient broth shows a slight 

 decrease of alkalinity, then a return to the original reaction. Broth 

 containing 2 % saccharose or glucose, gradually became acid ; lactose 

 broth showed little or no change in two weeks. 



Nitrates are not reduced to nitrites. 



Colour reduction. Litmus milk and rosolic acid peptone water 

 showed progressive bleaching during the first week, but the colour 

 finally returned. 



Toleration of sodium chloride. 3 % did not inhibit growth. 



Temperature relations. The optimum temperature is 25^30° C. ; 

 there is no growth at 5° C. ; growth is very slow at 3° C. Thermal 

 death point (wet) is 43-7° C, 10 minutes exposure. 



Desiccation. When organism was dried on cover glasses at about 

 20° C, 5 days had no effect, 76 days was fatal. 



Insolations. 10 minutes exposure of freshly poured plates retarded 

 development ; 30 minutes was fatal. 



II. Blossom Blight in England caused by Barker 

 AND Grove's Organism. 



This disease is very widespread in England, probably occurring at 

 least throughout the midland and southern counties. The most sus- 

 ceptible varieties are the Beurre d'Amanlis and the Catillac. 



The method of infection varies ; sometimes the sepals turn grey 

 and blacken, the discoloration finally involving the whole of the calyx 

 and flower stalk, and the flower blackens and shrivels up. It may 

 then fall or it may remain attached to the shoot. The whole truss 



