Maienschein Developmental biology has recently celebrated its centenary as a specialty within biology. The problems that were set forth at its creation, however, remain to be answered today. Far from being discouraged, however, developmental biology is, according to a centenary report in Science magazine, "basking in its prime. Indeed the excitement and promise of the field have never been greater, as researchers close in on the secret of how a single fertilized egg cell goes through the complex and beautifully orchestrated series of changes that create and entire organism." Under this grant, Dr. Maienschein is analyzing the changing ways the central issues of development have been addressed over the past century. Against a background of similar questions that these biologists were trying to answer, Dr. Maienschein is looking at how the significantly different details in approaches, methods, techniques, and different basic assumptions have pushed and pulled researchers in a variety of directions. She is focusing on issues of morphogenesis (how structural changes develop) in particular, and on the changing concepts of "organization" which have underpinned many of the discussions. Spotlighting and comparing selected examples illuminate the way the debates have shifted and some of the underlying epistemological assumptions that have accompanied the shifts. In this project, Dr. Maienschein will test the hypothesis that there have existed competing styles of thinking within this biological community. In particular, she argues, there emerge epistemic styles, each sharing fundamental epistemological assumptions about what will count as knowledge and how to warrant knowledge claims. These epistemic styles define and direct the scientific work and are contextually embedded, while those in each group share patterns of basic assumptions about the nature of science.