IN May 1934, an investigation into the brood diseases of bees was commenced at Rothamsted Experimental Station, the British Bee-Keepers' Association undertaking to supply half the annual cost of the work (£250 per annum) and the Agricultural Research Council the remainder. As a result, Dr. H. L. A. Tarr was appointed, and has worked continuously on the problem since that time. He has confirmed the fact that American foul brood is caused by a spore-forming organism, Bacillus larvce, and that its incidence is independent of the strength of the bee colony. European foul brood, on the other hand, is a disease which usually affects weak colonies of bees early in the brood-rearing season, and is probably caused by Bacillus pluton, a curious organism which has so far resisted all attempts made to cultivate it, in association with other organisms. He has also shown that a third condition known as addled brood is very, prevalent in Great Britain, and has constituted almost one third of the cases of brood disease sent in for examination. The Bee Research.Committee at Rothamsted and the British Bee-Keepers' Association are unanimously of the opinion that the investigation should be continued, particularly in connexion with methods of treatment, but the latter have asked that Rothamsted should collect the contributions directly. The Agricultural Research Council has sanctioned an increased grant of £300 for the current year on condition that a sum of not less than £250 is collected from other sources. In the circumstances, Rothamsted Experimental Station is making an appeal for contributions from interested individuals in order that this important investigation may be continued.