Keith R. Porter was a true pioneer in the field of cell biology. During his five decades as a research professor at some of the leading academic institutions in the United States, Porter played a seminal role as the discipline came into existence and reached maturity. Many of the most important discoveries in this new and dynamic area of study were made by Porter himself or by students, colleagues, and collaborators working in his laboratories. A native of Nova Scotia, Porter graduated in 1934 from Acadia University in Halifax. In 1938, he received a Ph.D. from Harvard University and then moved to the Rockefeller Institute in New York City to begin his work on cells in tissue culture. By the early 1940s, the Rockefeller Institute had become the crucible of the new fields of cell fractionation and fine structure. Porter, as head of the laboratory of cytology was at...