THERE can be few beekeepers in the heart of London, and one would not expect the Metropolitan area to be a promising locality for honey production. I therefore welcomed an opportunity of examining a sample of honey from an apiary in Kensington not far from Kensington Gardens, which was brought to my notice in 1943, on account of its unusual flavour. This honey was of a pale greenish-brown colour and after about three months in store set with a fine granulation. The first impression on tasting it was of a mild floral bouquet, but this was followed by a persistent after-taste reminiscent of cats. This flavour recalls exactly the cat-like odour given off by elder flowers (Sambucus nigra) when they are drying, and at first suggested that elder might be responsible. The pollens obtained by dilution in water and sedimentation were examined, but Sambucus pollen was absent. The most abundant, forming 44 per cent of the total, came from the Tree of Heaven, Ailanthus altissima, which is common as a street tree in Kensington. This species is diœcious, and the male flowers, especially, have a strong rather unpleasant odour recalling that of elder. A second major constituent was the sweet chestnut, Castanea sativa, the flowers of which also have a strong unpleasant aroma.