THE MOTH AND THE CANDLE 229 



as ornamental glories (the big-cats and others). The 

 stumpy tail of the lynx, of some monkeys, and some 

 lizards and fishes tells of a history in which the full- 

 sized tail became a " disharmony " a positive nuisance 

 and has been reduced, even if not abolished, by 

 natural selection of short-tailed or tail-less varieties. 



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 



