No abstract

. Summary -The effect of static magnetic fields on body size of Drosophila melanogaster was analyzed on 3 laboratory stocks reared under chronic exposure to a magnetic field 10-12-fold greater than the earth's. A significant increase in body size was observed which persisted even when the flies were returned to control environmental conditions after a few generations of exposure. The genetic basis of the differences observed between treated and control lines was assessed analyzing 2 fitness components and 4 dimensional characters. The increase in body size was mainly associated with cell number, suggesting that the magnetic field effect on size depends on genes which control cell proliferation.