The annual Congress of the Italian Biochemical and Molecular Biology Society (SIB) was held in September 1999 in Alghero, Sardegna, Italy. The programme envisaged a symposium on molecular adaptations of haemoglobin function in ver- tebrates. Haemoglobin specialists from several countries were invited to speak at the symposium and paved the way for wide-ranging and stimulating discussions. The symposium contributions have been collected together in this volume. The structure/function relationship in haemoglobins from vertebrates (fishes populat- ing temperate and polar environments, diving...