35 



two months; the spores also resisted the boihng temperature of 

 water for 15 minutes. From this it will be seen how great is 

 the .difficulty in curing foul brood unless the disease is attacked 

 in its early stages. 



" Sour brood " is distinguished from the other types of foul 

 brood by the absence of a spore bearing organism. 



Symptoms — When colonies are found to be weak and are 

 working languidly, with little desire to fly, foul brood may be 

 suspected. If it is present, an examination of the combs will, 

 show some cells (many or few) containing dying or dead larvEe, 

 andothers with their cappings sunken or perforated (see illus- 

 trations), the cells of healthy brood being usually compact, and 

 the larvse plump and of a pearly whiteness. 



When a colony is attacked by the strong smelling foul brood 

 {Bacillus alvei, Cheshire & Cheyne), th© larva begins to move 

 unnaturally and loses its characteristic plumpness and it-s white 

 colour assumes a flabby appearance and lies at the base or lower 

 side of the cell. The colour changes to pale yellow, then to 

 brown, and when the larva begins to decompose the mass 

 becomes paplike or gluey, and shows slight ropiness. The 

 difference in the decomposed larva depends on the proportion 

 of " sour brood " associated with this form of foul brood. If 

 the former predominates the mass is paplike, and if the reverse 

 is the case the decomposed larva is of a gluey and slightly ropy 

 consistency. In every case a most disagreeable stench, re- 

 sembling that given off by bad glue, is emitted, and in an 

 advanced stage of the disease the foul odour may frequently 

 be detected at a considerable distance from the hive. The foul 

 mass in the end dries up in the cells and leaves only a smooth 

 dark brown scale adhering to the lower side of the cell, and 

 this scale is difficult to remove. 



In the odourless foul brood {B. Burri, Burri; B. Branden- 

 burgiensis, Maasen; B. larvcR, White) the progress of the dis- 

 ease is much slower, as the larvse are usually affected at a later 

 stage, jusifc before or after they are sealed over. The diseased 

 larva lies extended on the bottom side of the cell, and soon 

 assumes a brown colour. The decomposed mass is odourless, 

 and on inserting a piece of stick into one of the cells, it will 

 have adhering to it on withdrawal a ropy coffee-ocloured mass, 

 which can be drawn out in a fine thread before it breaks. The 

 resultant dry scale, which is dark brown and rough, sticks to 

 the lower side of the cell. The cappings of the affected cells 

 are verj' much more depressed, are darker in colour, and some- 

 times perforated with irregular holes. 



In sour hrood (B. Gilntheri, Burri; Streptococcus apis, 

 Maasen) the larva is attacked while still curled up, and aiter 

 death it changes first to a greyish, and then to a yellow colour, 

 and there is a strong odour resembling that of vinegar. The 

 remains are easily drawn out of the cell without rupturing the 



