 It is sometimes assumed that scientific disciplines are sharply-delineated and can be defined by their subject matter. In fact, however, they are dynamically changing, shaped in large part by scientists, their research tools, and academic and research institutions. This is clearly true in the case of cell biology. Scientists began investigating cells in the seventeenth century after Hooke and van Leeuwenhoek reported what they saw with newly invented microscopes. Hooke (1665) gave cells their name. But the cell did not become a focal unit for studying biological processes until Schleiden (1838) and Schwann (1839) advanced the cell theory according to which cells are the basic living units. The term cytology was widely used for the studies that ensued, which focused mainly on describing cells as seen under the light microscope. Although Wilson used the phrase cellular biology in his introduction to Cowdry’s General Cytology (Cowdry 1924), and many of its contributors aspired to integrate disciplines studying cells, the term cell biology was only introduced in the years immediately after World War II. Those adopting the term cell biology advocated complementing new higher-resolution images created with the electron microscope with results from biochemical, biophysical, and molecular approaches to cells. This transition is exemplified in the naming of what would become the flagship journal in the field. The working title used in discussions about founding a new journal was Journal of Cytology. By the time of the first issue in 1955, it was called the Journal of Biophysical and Biochemical Cytology, a title chosen to emphasize the integration of multiple approaches to the study of cells. In 1962 it was re-christened The Journal of Cell Biology, by which time the International Society for Cell Biology and the American Society for Cell Biology had also been established and the term cell biology had acquired general currency for an integrated approach to cells. (Bechtel 2006: chapter 7, examines the establishment and renaming of the journal as well as the creation of the American Society for Cell Biology.)