5- Hydroxytryptamine

eral kinetic systems and compares their properties (after cautioning the reader of the possible pitfalls and of the assumptions which must be made) with various biological phenomena such as regulation, regeneration, determination , gene action, pleiotropism, etc. Few biologists have been as successful as Waddington in accomplishing a synthesis between embryology and genetics. In this volume, he brings his wide knowledge of these two fields into the framework of modern evolutionary thought in a concerted attempt to develop a theory of evolution which takes advantage of the concepts of developmental genetics as well as those of modern population genetics. and The Survival of the Adaptable is sufficient to indicate that some of the thorniest problems in modern evolutionary thought have been approached. (One of the essays, The Cybernetics of Development, is concerned largely with embryological problems, especially the canalization of development.) Waddington has been scrupulously careful to define terms and concepts as he uses them, and one of the great merits of the book is that it avoids much of the muddled thinking and careless use of terminology so common in present-day literature. He examines the contributions to modern evolutionary theory which have been made by the mathematical approach and concludes that, in spite of much enthusiasm for the method and the rather awestruck attitude toward it of nonmathematical biologists, it has contributed very little to evolutionary thought at the theoretical level. He makes this point repeatedly ". .. in order to overcome the anaesthetic effect exerted on biologists by algebra which is incomprehensible to them. There is no need for evolutionary theory to limit its view to those topics which have been successfully formulated in mathematical terms.. .. It is, perhaps, only if the biologist continues to do his best to cope with [mathematically difficult concepts]. .. with the imprecise but subtle tools of ordinary language that the mathematicians will eventually be driven to dissect them with their penetrating but relatively inflexible scalpels." Professor Waddington writes with his characteristic lucidity and elegance , which is marred only rarely by a passage of 'purple' prose (see p. 88). There are many controversial points in the essays, for Wadding-ton is an avowed neo-Lamarckian and tends away from the extreme atomism which is characteristic of much modern scientific thought. He has also dared to attack some sacred cows. Not every biologist will agree with all of Waddington's conclusions, but most will find …