ISLE OF WIGHT DISEASE IN HIVE BEES — PATHOLOGY. 
763 
Malden (2) was of opinion that “ the disease must be regarded as an infections one 
which primarily affects the chyle stomach.” 
The latter states that in his investigations “ no changes were discovered in the 
salivary glands, brain, fat body, tracheae, air-sacs, Malpighian bodies, or honey 
stomach,” but that “ the chyle stomach in many cases showed marked changes in 
section.” Of these changes in the chyle stomach the present investigation has seen 
little or nothing. Two exceptional cases have been noted where the epithelial lining 
had been definitely invaded. 
Malden, as a result of his bacteriological work, suggested a “plague-like” 
bacillus, called by him B. pestiformis apis, as the cause of the malady. He, however, 
made the suggestion with some reserve, and later, when his work had been over- 
shadowed bv the “ Nosema theory,” considered that toxins produced by various 
species of bacteria played an important secondary role in the disease. 
There is, however, an underlying truth in his summing up : “ The actual cause of 
death is uncertain, but it is probably brought about by malnutrition, possibly 
combined with the absorption of a specific poison and of the products of decomposi- 
tion in the colon, and probably aided to some extent by the imperfect oxygenation 
of the tissues, owing to the pressure exerted by the distended colon on the abdominal 
air-sacs.” 
Imperfect oxygenation, and possibly malnutrition and a toxic condition, are the 
main factors in the disease as we see them to-day. 
In this paper it has been sought to outline those pathological facts which have so 
far come to light, and to relate them as reasonably as possible to the action of the 
parasite on the one hand and the symptoms of the disease on the other. Certain 
points have been merely touched on and others left in doubt, but it is hoped that 
further details will be soon forthcoming. 
There are many to whom my thanks are due. To Dr J. Rennie, who, as director 
of the research, has been an inspiring leader throughout, I tender my warmest 
thanks for help and advice and much personal kindness. My sincere thanks are 
due to Professor T. Shennan and the staff of the Pathology Department, Marischal 
College, Aberdeen, who have given me every facility for carrying out this work. It 
was in the Pathology Department that the parasite was independently discovered 
on the 11th May 1920, and the theory of its significance in the disease formulated. 
I wish also to express my gratitude to Professor J. Arthur Thomson, Mr A. H. E. 
Wood, and the members of the Joint Committee of the University of Aberdeen and 
N. of Scotland College of Agriculture for all their interest and support. 
REFERENCES TO LITERATURE. 
(1) Imms, J. Board of Agric., vol. xiv, No. 3, June 1907. 
(2) Malden, Ibid., vol. xv, No. 11, February 1909. 
