Morphogenesis as influenced by locally administered magnetic fields.

An alteration in morphogenetic development induced in Drosophila melanogaster pupae by exposure to a magnetic probe was shown to persist for more than 30 generations. With succeeding inbred crossings, an initial increase in the time of development through the embryonic and postembryonic stages gradually approached the level found in control cultures. As the development time decreased, a concomitant increase occurred in the yield of progeny. The pattern of morphogenesis suggested a condition of homeostasis operating in an oscillating epigenetic system. The concept of a feedback control mechanism was employed to examine details of the alterations in development time. The data were compatible with this model and rates of recovery from an initial perturbation were determined in several series inbred for a large number of generations. Variations in rate constants and mechanisms involved in the magnetic field inhibition are discussed.