1909.] Disease of Bees in the Isle of Wight. 817 



described by Cheshire, since it seems probable that the depleted and 

 diseased occupants of the hive are unable to keep the temperature up 

 to the normal. So far as I have been able to ascertain, no observations 

 on the temperature conditions in diseased hives have been made. 



These observations show that the distention of the colon cannot be 

 regarded as a condition peculiar to the disease, and I think that, in 

 the later stages of the disease, it is far more probable that weakness 

 or disinclination to fly gives rise to overloading of the bowel, than that 

 distention of the colon produces inability to fly. Consequently, I regard 

 the condition of the colon as a secondary effect of the disease. 



The only constant difference observed was that the chyle stomach 

 of the affected bees was apparently more easily ruptured. This 

 difference was, however, not very marked, and could not be relied upon 

 in diagnosing the disease. 



The results of my gross anatomical investigations, instead of aiding 

 me, greatly increased the difficulty of investigating the disease, since 

 they showed that it was impossible to determine whether any given bee 

 was suffering from the disease, either by clinical signs or by coarse 

 dissection. 



Microscopical Examination of the Organs. 



Having failed to discover by dissection any definite and characteristic 

 changes by which the disease could be diagnosed, the separate organs 

 were carefully examined by means of unstained and stained microscopic 

 preparations and sections. 



No changes were discovered in the salivary glands, brain, fat-body, 

 heart, tracheas, air-sacs, Malpighian bodies, or honey stomach. Sections 

 and microscopical preparations of the wall of the colon showed no 

 changes. This portion of the gut contained pollen grains of various 

 kinds, masses of wax and bacteria. No differences were noticed between 

 the varieties of pollen grains found in the gut contents of normal and 

 diseased bees. Many of these pollen grains do not appear to have under- 

 gone digestion. 



The chyle stomach in many cases showed marked changes in 

 section. In the normal bee the cells of the lining membrane are 

 extremely well defined. In some diseased bees, presumably those in 

 the early stages of infection, many of the cells of the lining membrane 

 appeared swollen and ill-defined, and detached cells were seen in the 

 lumen of the gut. In more advanced cases many cells have become 

 detached, and of those which remained in position, the majority stained 

 badly, were vacuolated, irregular in shape, and possessed irregularis 

 staining nuclei. These changes were more marked in certain places 

 than in others. In the most advanced cases the cells had in some places 

 become completely detached from the basement membrane, while 

 everywhere the cells appeared greatly degenerated. The lumen was 

 filled with desquamated cells and granular material. 



No protozoa or worms were seen in any of the preparations. 



Bacteriological Examination. 



Smear preparations and cultures on various media showed the blood, 

 fat-bodies, tracheae, salivary glands, Malpighian tubes, etc., to be free 

 from bacteria. The disease is, therefore, not accompanied by a general 

 bacterial infection. 



A bacteriological examination of the gut contents was next under- 



