E. M. DoiDGB 79 



Resume of Salient Characters. 



Bacillus citrimaculans, n.sp. Causes spot disease of citrus, attacking 

 fruit and branch, rarely found on leaves ; attacks the parenchyma, first 

 occupying the intercellular spaces then breaking down the cell walls; 

 in nature attacks lemons, oranges and naartjes, and in addition has been 

 successfully inoculated into limes, shaddock, grape fruit, citron; Seville 

 oranges are resistant. 



A slender rod with rounded ends, 1 — 4 x -45 — -Tju-, average 1*5 x -5 

 to -G/i; motile by 5 — 10 peritrichous flagella; conspicuous capsule but 

 no spores ; involution forms in broth containing high percentages NaCl ; 

 stains readily by usual stains and exceptionally well with gentian violet 

 and by Gram's method. 



Forms showing sub-circular yellow colonies on nutrient agar with 

 dense, grumose centre ; hquefies gelatine, clouds nutrient broth, forming 

 pelhcle and sediment; does not liquefy blood serum; coagulates milk 

 with precipitation of casein and extrusion of whey, the coagulum is 

 not redissolved; no growth in Cohn's solution; characteristic growth 

 in Uschinsky's solution. 



No gas in fermentation tubes, acid with dextrose, laevulose, galactose, 

 maltose, saccharose and mannite, but not with lactose, glycerine, 

 dextrin, or starch. Nitrates reduced with evolution of gas; tolerates 

 up to 10 per cent. NaCl; no growth in broth over chloroform, indol 

 produced in media containing peptone. 



Aerobic, facultative anaerobe; killed by 60 minutes exposure to 

 sunhght; optimum reaction about 20 Fuller; T.D.P. 62° C, maximum 

 for growth 43° C. 



Group number 221.2321523. 



Summary. 



This paper gives an account of a citrus disease which is causing 

 considerable trouble in the Western Province of the Cape. It causes 

 dark sunken spots on fruit and shoot, and not only disfigures but pro- 

 vides an entrance for fungous parasites which completely destroy the 

 fruit. 



The causal organism is described at some length, and as it appears 

 to be one hitherto undescribed has been named Bacillus citrimaculans. 



The question of preventive measures is not discussed, but an 



