E. M. DoiDGK 77 



employed^ one half being covered mth black paper. To prevent the 

 effects of a rise in temperature, each plate was covered with a small 

 glass dish filled to a depth of 2 cm. with a 2 per cent, solution of potash 

 alum. The organism was killed by an exposure of 60 minutes and the 

 number considerably reduced in 45 minutes. 



Chloroform. The bacillus will not grow in nutrient bouillon over 

 chloroform. 



Germicides. The following table will serve to indicate the behaviour 

 of the organism toward the more common germicides : 



It will be observed from the above schedule that the organism is 

 very sensitive to copper sulphate, it is to be hoped therefore that good 

 results may be obtained by spraying the infected trees with Bordeaux 

 mixture. 



Pathogenicity to Animals. 



Through the courtesy of Sir Arnold Theiler, the pathogenicity of 

 the organism to animals was tested at the Veterinary Research Labora- 

 tories at Onderstepoort. I am indebted to Mr E. M. Robinson for the 

 following notes on experiments which he has carried out in this con- 

 nection. 



To test the pathogenicity of the Bacillus of Lemon disease, two 

 rabbits were inoculated each with half an agar slope of a 24 hours' growth 

 of the organism. One rabbit which will be called (A) was inoculated on 

 25th September, 1915, and the inoculation was given intraperitoneally. 

 This rabbit developed symptoms of extreme illness and on the two days 

 following the inoculation would not eat, refused to move and occasion- 

 ally made grinding movements with its teeth. On the third day after 

 the inoculation the rabbit appeared much less dull and at the end of 

 a week appeared quite well again. On the 7th October, 1915, the 

 rabbit received a further inoculation of half an agar slope (24 hours' 

 growth) subcutaneously, but showed no further s}anptoms of illness, 

 and is still healthy to date (14th November, 1915). 



Another rabbit (B) was inoculated with half an agar slope of the 

 organism (24 hours' growth) subcutaneously on the 25tli September, 1915. 



