742 DR JOHN RENNIE, MR PHILIP BRUCE WHITE, AND MISS ELSIE J. HARVEY 



In several other stocks showing the disease in an advanced stage, every bee 

 taken over a period extending to weeks, including drones, flying and crawling 

 workers, was found on examination to be infected. The flying workers were 

 frequently more heavily parasitised than were the bees of the same stock which 

 were unable to fly. 



These facts have shown us that " crawling " is only one of the phases of the disease 

 and that it cannot be dependent exclusively upon the intensity of the infection, as 

 shown by numbers of parasites ; it may be incidental, in part at any rate, to a critical 

 position of certain of the mites, so that oxygen starvation of groups of fibres of the 

 muscles of flight results. Evidence in support of this is brought forward in Mr 

 White's paper which follows, where also other possible factors are considered. 



The following Table summarises the typical results of our examinations of bees 

 for the presence of Tarsonemus. H. indicates that the stock from which the bees 

 were obtained was showing no indications of disease, and was described by the 

 owners as Healthy. 



S. stands for Sich stock, and invariably indicates that the ordinary symptoms of 



Isle of Wight disease known to bee-keepers were present. 



The figures 



quoted 



under the heading Tarsonemus indicate the number of bees in which Tarsonemus 



was found. 



Table I. 



Locality. 



Stonehaven 

 Edinburgh 

 Rubislaw 

 Aberdeen 



Kintore 



Northumberland 



Copford 



Shipton 



Cults 



Banchory 



Kirriemuir 



Huntly 



Glasgow 

 Drumlithie 



Cawdor 

 Aboyne 



Laurencekirk 

 Dingwall 



Aberdour, Fife 



Remarks. 



Developed the disease subsequently. 



No. 44 in record. 



Requeened. Reduced to 1 frame, 30th 



October. 

 Crawling marked. 

 Stock died out. 

 Infected artificially later. Became 



queenless. Died out subsequently. 



Died out from disease and queenlessness. 



Early stage of infection. Disease very 

 prevalent in immediate neighbour- 

 hood and robbing noticeable. 



No disease signs so far (30/12/20). 



A stock dwindling from the disease. 

 Minor tracheae were blocked. 



(4 stocks.) 



Last stock of 6,-5 of which have 

 already died of disease. 



An ordinary case. 



Stock much reduced and in bad condi- 

 tion, but no crawling had been seen. 



No record of disease in this apiary. 



