of cells; 6. Aging of animals: observations and questions- 7 

 Aging of animals: possible mechanisms; 8. Evolution and pro-* 

 gramming of aging; 9. Some judgments about the study of aging 

 It is significant that this book is published in a series de- 

 voted to developmental biology. The borderline between develop- 

 ment and aging is ill-defined, and both refer to systems under- 

 going progressive and usually Irreversible change with time. 

 Moreover, certain cell populations die early In the embryo 

 thereby contributing indirectly to morphogenesis or functional 

 equilibrium. This book, the first textbook ever written in this 

 area, is eminently suited for those developmental biologists who 

 want to learn the essentials of what is known about aging pro- 

 cesses, not least because it points the way to the important 

 literature in the field by means of carefully selected reference 

 lists . 



Although the treatment is in the main restricted to mammals, 

 and is of course selective, the breadth of scope attained within 

 these limitations will be clear from the table of contents. The 

 book is well illustrated. 



21. 



R.RUGH and L.B. SHETTLES . 1971. FROM CONCEPTION TO BIRTH, the 

 drama of life's beginnings 



Harper & Row, New York, etc. X,262 pp., many figs., subject in- 

 dex. $ 12.00 



This book was written for the educated layman, particularly the 

 prospective mother. The reason why we review it here is that an 

 attempt to make the facts of human development accessible to the 

 general public is bound to be of interest to professionals as 

 »;ell. The book is very readable due to a minimum of scientific 

 jargon, yet the authors have tried to be scientifically accurate. 

 In this they are not always perfectly successful, however. 



The book is in two parts, the first of which deals with human 

 development from conception to birth, including the necessary 

 groundwork of reproductive biology. Part two deals, among other 

 things, with pregnancy and prenatal care, various hazards to the 

 fetus, and genetical aspects. Although on the whole the text 

 serves its purpose very well, some criticism is possible. For 

 instance, in chapter 2 there Is some confusion over the polar 

 bodies, and the description of gastrulatlon, neurulatlon, and the 

 somite stages is extremely condensed and Inaccurate in various 

 respects. Moreover, there are several discrepancies between the 

 text and the figure captions and labels. In chapter 13 the sec- 

 tion on the molecular basis of inheritance is confusing and con- 

 tains several gross mistakes. The question of the genetic basis 

 of differentiation is posed but not properly answered. 



The illustrations of the book are very good. Particularly at- 

 tractive are a series of full-page colour photographs showing 

 human fetuses with and without membranes from 5 to 17 weeks. The 

 appendages listing embryonic ages as correlated with length and 

 weight, drugs and maternal diseases dangerous to the fetus, and 

 heritable human characteristics, and the extensive glossary are 

 very useful. The book is attractively produced. 



19 



