820 Disease of Bees in the Isle of Wight, [feb., 



Pathogenic Properties. — A single infection experiment was made 

 with a culture of this bacillus. A healthy stock of bees was placed 

 in a hive in a green-house. After a few days all the openings were 

 closed with muslin, and the bees fed on syrup. When the bees had 

 become accustomed to this treatment, broth cultures of the bacillus were 

 mixed with the syrup. Within a few days considerable numbers had 

 died, and specimens of apparently diseased bees showed the bacilli 

 in their chyle stomachs, which also showed the fragile condition found 

 in naturally infected bees. Distention of the colon could not be taken 

 as a diagnostic point, as this condition was found to be present in 

 healthy specimens of this stock taken from the hive before the 

 experiment was started. The majority of the bees showed no signs of 

 disease a week after feeding was commenced. 



Summary. 



Infectious Character of the Disease. — The history of the 

 spread of the disease throughout the Isle of Wight, the 

 characters of the individual outbreaks in various localities, 

 the results of experiments with healthy stocks and infected 

 hives and observations on natural infection in isolated hives, 

 together with the absence of any sufficient reason for suspect- 

 ing intoxication from food materials, all point strongly to 

 the infective nature of the disease. 



In the investigation of the disease many difficulties pre- 

 sented themselves. Bees sent for investigation in small 

 numbers, especially those in an advanced stage of the disease, 

 travel badly, and a large proportion of them are dead on 

 arrival. After death putrefactive changes set in rapidly, 

 especially in warm weather, rendering bees dead of the disease 

 useless for examination. Even those which arrive alive 

 seldom live more than a few hours. In such cases the 

 examination of specimens had to be undertaken without 

 delay, often at very inconvenient times. In addition to these 

 difficulties it was often impossible to obtain any specimens 

 for considerable periods owing to apparent temporary cessa- 

 tions of the epidemic. At a later period a stock of diseased 

 bees was obtained through the kindness of Mr. H. M. Cooper, 

 and kept under observation at Cambridge. 



Presuming the disease to be infectious, it was necessary to 

 keep these bees in confinement under artificial conditions, 

 the hive being placed within a muslin cage and the bees fed 

 on syrup. How far these conditions influenced the course 

 of the disease in this stock it is impossible to say. 



