Family Treasures

This is a book, designed for popular consumption, that lists a number of normal characters held to be inherited in man. Many traits are scarcely "treasures," as might be inferred from the title. They pertain chiefly to physical characters, especially those of the face and other readily inspected areas. Much of the material would appear to have been obtained from students in the author's class of genetics who have used freely their family albums in documentation of the traits possessed by their ancestors. The value of this book lies in its variety and number (234) of illustrations, which are largely of good quality, and in the fact that it contains many suggestions as to normal features that can be observed by one who wishes to study human inheritance. The number of entities that had been made available previously for use in this regard is unfortunately small, for example, blood types and groups, dermatoglyphics, ability to taste phenylthiocarbamide, and the presence of mid-digital hair. From the scientific standpoint this work suffers from the absence of quantitative methods, from oversimplification , and from an uncritical viewpoint. Many of the traits described as recessive or dominant are probably controlled by multiple factors and were tested inadequately to permit the conclusions drawn. A typical instance of this is the acceptance of the form of frontal hair line as a somewhat standard condition despite the known occurrence of changes related to sex and age. The title states the problem to which this book is devoted and there is no one more capable of discussing the subject than the author who, a little over ten years ago, published an extensive work on Chemical Embryology. The book is more than an excellent assembly of the contributions which have been made in recent advances in modern experimental embryology. It centers around the fact that living as well as non-living substances when introduced into the early developing embryo can bring forth in the host new centers for organization and development. This invites biochemical investigations of what may be called morphogenetic hormones and the author points authoritatively to the 'bridge now being constructed over the gap between morpho-genesis and biochemistry in development. The book is divided into three parts, the first of which deals largely with the chemical constituents and environment of the egg and embryo. The second and largest section takes up the various morphogenetic stimuli which are involved …