1921.] '■ Isle of Wkiht " Piskask of Befs. 79 



affected stocks in the Island had by that time (hed otT, and that 

 the disease remained in abeyance until the middle of June, 

 when it broke out again with greater virulence. They formed 

 the opinion that the conditions described by Mr. Imms were the 

 result and not the cause of the disease. They also shared the 

 opinion of the practical bee-keepers on the Island, that the 

 disease was highly infectious and that the drinking places visited 

 by the bees were a source of contaiuiiiation. 



In 1911, the disease made its appearance in England and 

 Scotland. Dr. Maiden continued his work and was assisted 

 by Dr. Fantham, Dr. Annie Porter, and Mr. Bullamore. The 

 general conclusion which these investigators arrived at was that 

 the disease appeared to be caused by a parasitic organism, 

 " Nosema Apis." a member of the group known as *' Micro- 

 sporidia," which carried out its life cycle in the intestines of 

 the bee. The name Microsporidiosis " was accordingly given 

 to the disease. Inv^estigators in other countries. Zander and 

 Massen in Germany, and Nussbaumer in Switzerland, also came 

 to the conclusion that *' Xosema Apis " was the cause of the 

 disease. 



Attention was now devoted to finding a cure for it. 

 Several drugs were tried with varying results, but no definite 

 and certain remedy could be found. Investigations were then 

 carried out at the University of Aberdeen and the Aberdeen Col- 

 lege of Agriculture by Dr. Rennie and Mr. Anderson, the latter 

 eventually questioning whether " Nosema Apis " was, in fact, 

 the cause of the disease. Dr. Rennie was later assisted by Miss 

 Elsie J. Harvey and Mr. P. Bruce White, B.Sc. Their investiga- 

 tion led to the discovery, early last year, of a parasite of a remark- 

 able kind, belonging to the genus " Tarsonemus/' hitherto 

 unknown in bees. The Tarsoncmrs include several species 

 destructive to plants, and there are some which have been found 

 in malignant growths in man and in animals: in structure the 

 bee Tdrsoncine appears to be most closely allied to these last. 

 This creature, which is specialised in structure, is hrvd witliin 

 the bee and is confined to an extremelv limited, hut verv im])or- 

 tant i-egion of its breathing system. Within the space of a few 

 cubic millimetres scores of these creatures may be found in all 

 stages of development, sometimes so densely packed as to cut 

 off effectively the air supply from the surrounding organs. Tlu^ 

 det-Mled pathology described in Mr. White's paper ])roved the 

 destructive character of the parasite's habits. Thousands of bees 

 hqve he*^n examined from large numbers of stocks throu«_diout ^he 



