LABOURERS in factories in South Malaya who cut up pineapples by hand for canning invariably show an abnormality of those parts of the body which are exposed to slight pressure and pineapple juice, notably the palmar surfaces of the fingertips and the periphery of the palms. At the beginning of the canning season, the left hand, which comes more into contact with the fruit than the knife-holding hand, becomes sore and small superficial raw areas on the fingertips are often seen. Within several days, however, these heal, and the skin ceases to be sore. The labourers state that this tolerance to the pineapple juice is due to the development of an abnormality of the skin, which in the affected area becomes bluish-white and so smooth that fingerprints may be completely lost. Deep cracks are sometimes seen in the region of the skin creases. These often stay raw and bleeding for a long time, and show no clinical signs of infection, presumably because of removal of dead tissues by enzymatic action.