600 Transactions of the Society. 



They grow extremely slowly in coagulated blood serum, though 

 kept at the body temperature, and there form very long filaments 

 (see fig. 9) with comparatively few spores. 



In meat infusion kept at the temperature of the body they grow 

 readily, causing muddiness, and after a few days a slight but not 

 tenacious scum. The same peculiar odour is also developed here, 

 more especially if the infusion contains a considerable amount of 

 peptone. I do not think that there is any change in the reaction 

 of the fluid; I generally make the infusions faintly alkaUne, and 

 after the growth of this organism in it it is faintly alkaline. 



These characteristics show that this is a new bacillus, and one 

 which, so far as my knowledge and experience goes, is only found 

 in foul brood. The constant presence in large numbers of a cha- 

 racteristic organism in a disease and its absence elsewhere must, 

 according to our accumulating experience, afford a strong pre- 

 sumption that the organism is the cause of the disease. In the 

 case of foul brood this matter has been completely proved by the 

 following experiments, the details of which will be found in Mr. 

 Cheshire's part of this paper. With a cultivation in milk he sprayed 

 a comb containing a healthy brood, allowing the spray to act only 

 on a particular part of the comb. This part and no other became 

 afieoted with foul brood. He has also succeeded in infecting adult bees 

 by feeding them with material containing these cultivated bacilli, 



I have also had the opportunity of watching the effect of feeding 

 flies with material containing spores and bacilli. I was one day 

 testing some milk in which these bacilli were growing; a large 

 bluebottle fly settled on it and commenced to eat. I at once put a 

 large glass funnel over the insect, leaving plenty of air. When I 

 came to the laboratory twenty-two hours later the fly was in the 

 sitting posture on the table and was dead. Its juices were full of 

 these bacilli, as shown by microscopical examination and by 

 cultivation. 



Other animals which I have tested are more or less refractory 

 to this bacillus. I have kept cockroaches for days in a box in 

 which was milk containing these bacilli mixed up with sugar. I 

 have also kept them in a box containing a piece of paper which 

 had been thoroughly smeared with the spores. None of them died, 

 but I cannot be certain that in either case they ate any of the 

 material, for I never saw them even near it, 



I inoculated two mice and one rabbit with a spore-bearing 

 cultivation without efiect, 



I injected half a syringeful of a spore-bearing cultivation into the 

 dorsal subcutaneous tissue of each of two mice. One of these died in 

 twenty-three hours, the other seemed unaffected, but in the second 

 case I doubt whether the full quantity was introduced. In the 

 case of the mouse which died the seat of injection and the neigh- 



