Melanism in the Lepidoptera and its Possible Induction

Abstract

BELIEVING that light can be thrown on some of the problems of evolution by an experimental investigation of the development of melanism in lepidoptera, we have been studying the influence of the food plants growing in critical areas, and also of inorganic substances likely to occur in or on the plants of such regions, on races of moths imported from non-melanic districts. Our cultures have been reared at two centres; some at Birtley (Durham), an area producing a very large number of melanic species, and others at Hexham (Northumberland), where melanism is much less prevalent, although not absent. The work is not finished, but certain facts seem worth publishing at once, particularly in view of the recent controversy as to the value of Kammerer's experiments.