MALDEN, FEBRUARY, 1909. 87 



9. Tho conclusion drawn is tliat in a knowledge of the causes of 

 bee diseases lies ho])o for their control. 



Malden, February, 1909. 



In 1909 Dr. Maiden, of Cambridge, England, made a report* 

 on his investigations of a disease which appeared on the Isle of. 

 Wight. A paper by Imms (p. 79) discussing this disorder has already 

 been considered. 



Maiden w^ent to the island in May, 1908, and by interviewing the 

 bee keepers and inspecting colonies found that the disease had appar- 

 ently^ quite died out. The disease had been seen, however, in March 

 and early April of that year. After a short period of apparently 

 complete absence tlio disease again appeared about the middle of 

 June, 1908. 



Maiden states that as a rule the disease causes greater losses during 

 the summer than in winter. The reverse, however, has been noted 

 at times. May and June are according to most observers the months 

 durmg which the disease is usually most rapidly fatal. Infected 

 colonies are not always destroj^ed. They may recover but are sub- 

 ject to a later attack by the disease. 



Maiden's investigations into the cause of the disease include a 

 study of the gross and microscopical anatomy of the diseased bee, 

 together with a bacteriological study of it. In his bacteriological 

 study one species was encountered to w^hich, on account of its resem- 

 blance to Bacillus pestis, the supposed cause of bubonic plague, he 

 gave the name Bacillus pestiformis apis. The morphology, cul- 

 tural characters, and pathogenic properties of this bacillus are 

 given as follows by ^Maiden : 



It is an aerobic, non-motUe, Gram negative, non-acid-fast, short, broad bacillus, 

 varying in its morphological appearances upon different media. No flagella could be 

 demonstrated. On agar it grows fairly well, forming in twenty-four hours medium- 

 sized (largest 0.1 cm. in diameter), round, white or slightly yellowish, smooth, glis- 

 tening, flattened, dome-shaped colonies. On further growth the colonies do not 

 increase much in size, and unless very thickly sown they show little tendency to 

 coalesce. After twenty-four hours' growth the bacilli are of medium length (1-1. 5/i), 

 broad, and with distinctly rounded ends. Many of them are distinctly oval. They 

 have a tendency to stain better at the ends than in the middle (polar staining). Occa- 

 sionally the lightly staining central portion appears as a distinct band, especially 

 when the organism is lightly stained. After seven days' growth very little general 

 change is noticed, though a few large involution forms make their appearance. On 

 gelatin growth takes place rapidly in the form of colonies, resembling those produced 

 on agar. The organisms are more rounded than on agar, being distinctly oval in shape, 

 and polar staining is not so marked. On -potato a considerable raised cream coloured 

 growth is produced in twenty-four hours at 37° C, which continues to spread. The 

 bacilli are larger than when grown on agar, but the light central band is not quite so 



> Maiden, Walter, M. A.,M. D., February, 1909. Further report on a disease of bees in the Isle of Wight. 

 Journal of the Board of Agriculture, Vol. XV, No. 11, pp. 809-825. 



