The fact that about half of our readers are not biologists does not mean that they are disinterested in the fascinating current developments in the field of biology any more than the biologist are disinterested in the equally fascinating progress of materials science or physics. Popular press and even trade journals often over simplify or at best give small pieces of information. It is nice when a refereed journal gives a state of the art review. Science Magazine recently gave such a review under the title "Development Frontiers in Biology". As is customary with Science, this issue also contains editorial summaries of many of the contributions in less technically obscure language.