t 



DETERMINATION OF AGE IN HONEY-BEES. 193 



It must be remembered that yeasts are very widely, distri- 

 lauted organismSj so that hardly a bee examined will be free 

 from small numbers taken in with pollen grains, etc. They 

 are usually, of course, quite harmless, and it is only when 

 conditions are suitable for them to pullulate that they appear 

 to have any pathogenic effect. 



(3) After a bee has been free in a room for even a short 

 time 1 have found that it almost invariably develops one or 

 more colonies of a mould. Branches of the mycelia of these 

 often penetrate the walls of the alimentary canal, causing 

 adhesions between its various parts and rapidly proving 

 fatal. The spores of these fungi are no doubt ingested by 

 the bee with dust from the room. 



(4) The black shiny condition occasionally meb with in 

 some bees of a stock owing to loss of the normal covering of 

 hairs has been associated by Cheshire (2, ii, p. 570) with the 

 presenceof an organism — Bacillus gay toni — in the intestine. 

 This finding has not so far been confirmed. Cheshire states 

 that in such cases the queen is generally badly affected and 

 that re-queening is the best way of checking the disease. 



In addition to these' there would seem to be at least one 

 ■other disease for which a specific organism has not yet been 

 separated. This I shall refer to provisionally as malignant 

 disease.^ Rennie (17) has recently published some interesting 



' It is better to avoid the use of the term " Isle of Wight " disease 

 ■owing to the confusion associated with it. This mysterious unknown 

 disease (malignant disease) has been much confused with miorospori- 

 •diosis. Further, one or two instances in which yeasts, have been 

 mistaken for Nose ma by incompetent observers posing as experts have 

 ■come under my notice. Thus at times at least thi-ee of the above dis- 

 orders have been called " Isle of Wight " disease, and it is now, I fear, 

 impossible to determine with certainty to which the term was originally 

 applied. 



Much has been written also about bee paralysis, but I can see no 

 reason for considering this to be a distinct disease. Supposed isolated 

 instances are doubtless often due to accident — the result of fighting 

 amongst themselves or with wasps, etc. — age and cold, or, as Maiden 

 (7a, p. 135) points out, many so-called cases are in reality cases of the 

 above (malignant disease). 



