34 



transmitted, the following experiments were carried out at our 

 Research Apiary : — 



(a) About 200 bees crawling on the ground, and showing 



abnormal distension of the abdomen, were collected, 

 chloroformed, and the liquid contents of the intestine 

 removed. This fluid, mixed with a pint of sugar 

 syrup, was systematically fed to healthy colonies until 

 the crawling symptoms were evident. The colonies 

 thus fed contracted the d'isease in a virulent form in 

 from three to six weeks. 



(b) Colonies in the last stage of the disease were united to 



healthy colonies by placing all the sick bees, combs, 

 brood, and stores in the form of an additional brood 

 chamber over the top of unaffected stocks. (The queens 

 in the diseased colonies were removed previous to the 

 union.) It took from 4 to 6 weeks to transmit the 

 disease by this method. 



(c) The entire brood chambers from colonies that had 



recently died from Isle of Wight disease were placed 

 over the brood chambers of healthy colonies (as in the 

 operation of uniting or doubling). The infected 

 brood chambers, which contained faecal matter in 

 abundance on the frames and over the combs, and 

 many dead bees in the cells, were not interfered with. 

 The chamber was necessarily used by the bees as a 

 honey super. This compelled the healthy bees to 

 remove the dirt and debris from the soiled combs, and 

 brought them in direct contact with disease-infected 

 material. The time of infection in this case was 

 longer — from 6 to 8 weeks. 



(d) Combs from colonies where the bees had recently died 



from the disease were broken up and mixed with 

 water. The extract, after being strained through 

 coarse cloth, was mixed with sugar syrup and fed to 

 healthy colonies. In this case infection was even 

 slower — from 8 to 10 weeks. 



