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Human haemoglobin, like the domestic pea, is one of the cornerstones of the building of genetics. The Garrod-Bateson concept of one gene one enzyme arose in the early I900's from the study of a few metabolic diseases. The refinement of this to the concept that one triplet of bases length of DNA codes one amino acid developed from the work starting in the late I940's by Pauling, Ingram, Kendrew, and others on the structure of normal and abnormal haemoglobins simultaneous with the development of the Watson-Crick model of DNA. Lehmann and Huntsman have written a most attractive account of the haemoglobin and its variants, describing not only the molecular, clinical, and pathological aspects, but also something of the contribution of the study of haemoglobins to population genetics, evolution, and anthropology. The haemoglobin of the lug-worm is saturated at only 4 mm. oxygen tension. The more complex molecules made of several haemoglobin units characteristic of vertebrates have the advantage of a sigmoid dissociation curve. The closer two animals are taxonomically, the more similar will be their haemoglobins. The sites of attachment of the vital haem groups are evolutionarily conservative; even the carp and man have some amino acids in this region in common. The horse, pig, and rabbit have polypeptide chains differing from the human chain by about 20 amino acids in each chain. Man and gorilla have two amino acid differences in their a chains and one in their ,B chain. Man and chimpanzee have no detectable differences in either chain. The gene for the a chain is oldest, and it is suggested that from a duplicated a chain gene was derived the gene for the y chain, which in turn gave rise to the 1 gene which more recently still gave rise to the 8 gene. The 1, 5, and probably the y gene locus are closely linked. Minor haemoglobin variants, depending usually on single amino acid substitutions, contribute not only to the understanding of the racial relations in man, but also, for example, of the relative contributions of the tropical humped cattle and the European aurochs to domestic breeds, and of the origins of domestic sheep. Haematologists will welcome the detailed descriptions of techniques which form the last third of the book and are based on the authors' very extensive experience in the detection of abnormal haemoglobins. A much wider group of geneticists and medical practitioners will find this a book which they greatly enjoy reading and wish to have on their own shelves. C. 0. CARTER