16 HISTORICAL NOTES ON BEE DISEASES. 



mild and virulent foul brood is, that virulent foul brood is caused 

 by a fungus which he named Cryptococcus alvearis, and that the mild 

 foul brood is due to some other cause. His conclusion concerning 

 the virulent foul brood was reached tlu-ough a microscopic study of 

 foul-brood material. Preuss had been somewhat familiar with bee- 

 keeping since early boyhood, and had had the opportunity of visit- 

 ing numerous apiaries in the Vistula Valley, but had not encountered 

 foul brood until in 1866, when a friend had called his attention to the 

 disease m an apiary of the latter in which he was using the Dzierzon 

 hives. Preuss immediately undertook the investigation of the char- 

 acter of the disease by study mg microscopically the larvae wliich had 

 died of the disease. A small bit of the dead larvae was added to a 

 little water, covered with a glass, and studied in the fresh condition. 

 Numerous spherical bodies measuring 2 // in diameter were seen and 

 identified by him as belonging to the genus Cryptococcus, to wdiich 

 he gave the name Cryptococcus alvearis. Larger objects wliich were 

 present were recognized as fat bodies. 



Very nearly related to this organism, Preuss writes, is a fungus 

 that causes fermentation, Cryptococcus fermentum. It was his belief 

 that if this latter species infected or fell upon a larva it might, under 

 favorable temperature and moisture conditions, change into Crypto- 

 coccus alvearis and in this way produce foul brood. Practical bee 

 keepers had, prior to this time, emphasized the danger of foul brood 

 transmission by the feeding of fermented honey. One bee keeper of 

 large experience had attributed foul brood to meal feeding, and since 

 meal is a good medium for the growth of fungi, Preuss was inclined 

 to favor the view. He argued that since the fungus of fermentation 

 is widespread in nature, the brood dying from cold or neglect of any 

 kind may constitute a fruitful soil in which this fungus could grow 

 and thus become the cause of infectious foul brood. Medication in 

 the treatment of the disease Preuss held to be quackery and recom- 

 mends instead the removal of the diseased frames from the hive, but 

 not the destruction of the hives. The hives were to be washed with 

 10 per cent sulphuric acid, followed by water, and afterwards put 

 into an oven and heated to the boiling temperature for some hours. 

 The frames containing diseased material were to be burned, and 

 those frames which w^ere free from such material were to be used 

 again. All dead bees were to be buried, as they might become a 

 source of fungous growth, and the ground in front of the hive was to 

 be sprinkled with sulphuric acid and then dug up deeply. 



SCHONFELD, NOVEMBER 15, 1873. 



In the absence of conclusive experimental proof, the theories 

 advanced by Preuss in the paper just considered were not univer- 



