Organisers and Genes

THE student of heredity is confronted with two different groups of problems. The first group, including such questions as: ‘Why do two white mice produce another white mouse, but not a black or a brown one?’ has been answered, at least up to a point, by the geneticists. The second, typified by such a question as: ‘Why do two mice produce a mouse, and not a rabbit, a mass of Protozoa, or a sarcoma?’ has been answered much less satisfactorily. Genetical results have great practical value in the fields of agriculture, eugenics, and evolution, even if they are not appliedto the study of development. But genetics will remain a somewhat isolated branch of biology until this is done.Organisers and GenesBy Dr. C. H. Waddington. (Cambridge Biological Studies.) Pp. x + 160 + 2 plates. (Cambridge: At the University Press, 1940.) 12s. 6d. net.