We have to be careful in asserting that any structure or behaviour in an organism is certainly a "disharmony," for it is very difficult to be quite sure as to the complete details of the life of a wild creature, and so to be able to form a conclusion rather than to suggest a possibility--as to the part played by an apparently injurious structure or habit in the economy of that creature. One of the most striking instances of a habit or behaviour which persists and dominates the life of a wild animal to its own injury and destruction is that shown by many moths and other insects, which are attracted at night by a flame (a lamp or an open fire), and fly into it even when burnt by it, again and again until they are killed. A burnt child dreads the fire; but a burnt moth or a singed ichneumon fly seems to enjoy being burnt, and becomes more and more excited by its dashes into the flame until it finally drops with shrivelled wings to the ground. My brother told me some years ago of the verandah of his house in Java in which an open lamp was lit every night. Regularly two sets of animals, driven and guided by the action of the light on their nervous mechanism, arrived on the scene. Swarms of moths and flies dashed in and out of the flame and fell, maimed by the heat, to the ground. There a strange group had already assembled. Gigantic toads and wall lizards crept from their holes in the masonry and woodwork, and awaited the shower of injured insects, which they snapped up in eager rivalry as the infatuated flame-seekers dropped, hour after hour, to the floor. The instinct, the nervous mechanism, which brought the greedy reptiles to the spot was a "harmony," a valuable guide to nutrition; whilst the flame-seeker's impulse is assuredly a "disharmony"--a defect in adjustment--leading to death.