566 PROCEEDINGS OF SECTION G2. 



plant so treated, we were unable to discover which was which, 

 as the vines looked all equally healthy and vigorous. 



There is little doubt that for some time after the application 

 the ferrous sulphate acts as a fungicide, but after a while it is likely 

 that its composition undergoes a change. Under the influence of 

 the complex ingredients of the soil, it may be assumed that the 

 sulphate of iron will finally produce ferric oxide and some alkaline 

 sulphate, probably potash sulphate. The application of ferrous 

 sulphate to the soil would in consequence have an effect similar to 

 that which is attributed to gypsum, and we know that the 

 latter substance is a vigorous stimulant to vegetation. 



9.— ACUTE BOVINE CONTAGIOUS MAMMITIS DUE TO BACILLUS 

 LACTIS AEROGENES. 



By PROFESSOR J. A . GILRUTH, D. V. Sc. ,M.R.C.V.S.,F.R.S.E., and NORMA N MA CDONA LD, 

 B.V. Sc, from the Veterinary Institute, Melbourne University. 



The paper records an outbreak of a contagious form of acute 

 inflammation of the udder, due to the Bacillus Lactis Aerogenes. 

 The bacillus in question, although common in dairying premises, 

 and particularly in piggeries, has not heretofore been considered 

 pathogenic for cattle, and is not so when introduced by the alimen- 

 tary canal or subcutaneously. In this instance, however, it has 

 been isolated by the authors from the outbreak in question, culti- 

 vated, and proved to be the causative organism by the reproduction 

 of the characteristic features of the disease in experimental cows 

 when introduced into the milk ducts of the lactating udder. Pre- 

 liminary experiments conducted indicate the possibility of pro- 

 ducing an anti-toxic serum which may prove useful in the treatment 

 of ordinary cases, and these experiments are being continued by 

 the authors. 



The outbreak of mammitis dealt with was undoubtedly spread 

 by the careless management and insanitary conditions of the 

 milking machine employed on the farm, and this emphasises the 

 necessity for the utmost care in attending to the cleanliness of such 

 appliances. 



