[Originality and biogeographical specificities if intertropical zones]

The author gives a synthesis of original and specific characteristics of inter-tropical zones, abiotic (climate, soils) and especially biotic data: biodiversity originality, adaptations, ecosystems. He concludes his review by considering the richness of biological interactions (with two or three partners) as well as the biotic systems with parasites and hosts and the struggle against parasites of ecological (via bioindication) or biological nature.