Modern Alchemy

developmental process. Surveying the mathematical analysis of Woodger and the contribution of experimental embryology to formation (Gestaltung), to segregation, to differentiation, to growth, to polarity and symmetry, and finally to regeneration, we are led through a consideration of the historical character of the organism to the system theory. We read, "We must view the germ as a whole, as a unitary system, which accomplishes the developmental processes on the basis of the conditions which are present in it and depend on the organization of its material parts." This survey should be a part of the armamentarium of all who possess a driving interest in living organisms whether it be volvox or man. No one should undertake investigation into life processes, be they physico-chemical or psychological, without a grasp of the material so clearly summarized in this book. H. S. BURR.