Ticc-liff pinq ill Victoria 



material for the experiments. Larva-, sick and dead, of sacbrood were 

 picked from the combs, crushed, and diluted with sterile water. This 

 suspension was filtered by the use of the Berkefeld filter. From each 

 of the three diseased colonies a separate filtrate was obtained, which 

 was fed in syrnp to healthy colonies. Six colonies were thus fed — 

 two with each of the three separate filtrates. As a result of these 

 inoculations sacbrood with typical symptoms of the disease was pro- 

 duced in all of the six colonies thus fed. 



" One more experiment will be mentioned at this time. In this the 

 diseased brood used was taken from one of the colonies in which the 

 •disease had been produced by feeding filtrate. Disease material from 

 this colony was filtered as before and fed to two healthy colonies, with 

 the result lliat sacbrood was produced in each. It might be mentioned 

 here also that other experiments made indicate that the virus is killed 

 by the application of a comparatively small amount of heat. 



" In eleven colonies, therefore, sacbrood has been produced experi- 

 mentally by feeding to healthy colonies the virus of this disease. In 

 tight of the eleven colonies the disease was produced by virus that had 

 passed through the Berkefeld filter. The disease, therefore, which bee- 

 keepers have for a long time recognised as being different from either 

 American or European foul-brood, has now been demonstrated to be 

 an infectious disease that is caused by a filterable virus. 



" The conclusion to be drawn from this work, therefore, is that 

 sacbrood is an infections disease of the brood of bees caused by an 

 infecting agent that is so small, or of such a nature, that it will pass 

 through the pores of a Berkefeld filter. 



" The three principal brood diseases, then, are now all known to 

 be infectious. These diseases are — American foul-brood, caused by 

 Bacillus larvw; European foul-brood, caused by Bacillus lyluton; and 

 sacbrood, caused by a filterable virus." 



Diseases of Adult Bees. 

 "While the causes of brood diseases of bees are well known, the state 

 of our present knowledge of the diseases of adult bees is much less satis 

 factory. The latter are three in number— Paralysis, dysentery, and 

 disappearing trouble. 



Bee Paralysis. 



This is a disease of the adult bees, the cause of which is still un- 

 known. The first indication is the presence in the colony of a few 

 shiny, emaciated looldng bees; these are still capable of flight, and 

 some will go foraging, but they often fail to return, remaining on 

 flowers and other objects and die. Later on numbers of bees with 

 abnormally inflated abdomens will be noticed in the hive. They may 

 be noticed about the hive entrance, their wings and legs extended side- 

 ways, giving them a sprawling appearance. Their movements are 

 jerky, and their wings quiver at intervals. When a hive is opened 

 •some of the bees so affected will, after a few minutes, come on top of 

 the frames. When smoke is blown amongst the bees they remain or 

 top, while the healthy ones run down between the combs. After 

 paralysis has been present in a colony for a considerable time even the 



