52 Proceedings of the Royal Physical Society. 



We recognise that Nosema may be a contributing weakening factor 

 favouring in certain cases the development of this disease. But we have 

 not found that it is an essential factor. 



IV.— OBSERVATIONS AND EXPERIMENTS BEARING ON THE 

 INFECTIVITY OF ISLE OF WIGHT DISEASE. As 



DISTINGUISHED FROM MiCKOSPOKIDIOSIS. 



{a) Attempts to Produce Isle of Wight Disease by Artificial 



Infection. 



No. 1. Tolsta Experiment. July 1914. 



The stock utilised in this experiment was a small swarm of unknown 

 race, originally imported from the South of England. It was transferred 

 for the purpose of this experiment from the Nicolson apiary to Tolsta 

 which is six miles from the nearest hive of bees. A control examination 

 gave a negative result as regards Nosema. 



On 18th July 1914, three large lots of " crawling " bees, numbering 

 hundreds, were taken from the stock at Bayble suffering from Isle of Wight 

 disease (see p. 46). These were beaten into a compost with honey and 

 spread over the tops of the combs of the Tolsta bees. When the hive was 

 visited on the 27th July everything had been cleaned up by the bees. There 

 was no trace of the honey nor of the mashed-up bodies. The bees were 

 multiplying and required extra combs. 



On 19th August, they covered fully eleven combs and had gathered 

 considerable stores of honey. Not a " crawler " was visible, nor even a 

 single dead bee to be seen in front of the hive. Samples at this date 

 were examined by Innes who reported: — "Bees alive, active. No Nosema 

 spores found." 



On 12th September, the bees were found to fully occupy twelve combs, 

 and not a dead bee was to be seen. There were no indications of any 

 kind suggestive of Isle of Wight disease. 



On 17th October, one fully sealed outside comb of honey was 

 removed leaving eleven combs loaded with honey. The bees were in 

 excellent order. 



On 7th November, the Tolsta bees were again visited. It was a fine 

 mild day and the bees were flying freely. Several drones were observed in 

 flight, but these were being attacked by the workers. The presence of 

 drones so late in the season probably indicated that the queen was 



