[Structure variations of short polytene chromosomes in 2 pyrenean populations of Bilobella aurantiaca Caroli (Collemboles)].

Structural variations of the short polytene chromosomes VI and VII occur in two Pyrenean populations of Bilobella aurantiaca. They are the result of longitudinal cleavage and also of variations in the number of the thin bands. They are not dependent on ecological factors, but often correlate with the chromosome polytenic stage.