[The polymorphism of the polytene chromosomes of Bilobella aurantiaca Caroli (Collemboles) and its biogeographic and ecologic significance].

Collembola Bilobella aurantiaca lives in forest biotopes all around the western Mediterranean sea; it shows a great polymorphism of polytene Chromosomes (2n = 14). This polymorphism is founded on differences of band-pattern and overall on alpha-heterochromatic overcharges at certain points. Examples are given for the chromosome VI. The chorology of this species does not permit an explanation of the division of most of the chromosomal types which seem to be closely linked with the ecological components of the biotopes.