Proceedings of the Royal Physical Society. 
Or 
INS) 
We recognise that Mosema 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] 
DISTINGUISHED FROM MICROSPORIDIOSIS. 
(a) ATTEMPTS TO PRODUCE ISLE oF WIGHT DISEASE BY ARTIFICIAL 
INFECTION. 
No. 1. Tolsta Expervment. 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 Wosema 
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 
