Why is this journal called Protoplasma? A history of protoplasm theory and the divisions in cell biology before 1926.

When the journal Protoplasma was founded 100 years ago in 1926, scientists used two different concepts to describe what we would now consider one and the same object: the cell for the membrane-bound structural unit of life, and protoplasm for the living fluid mass or body of the cell. The flourishing of both concepts together dates back to the 1850s, when biologists revised the original cell theory of 1838/39 while also unifying the definition of the cell across plant and animal kingdoms. However, at the beginning of the 20th century a methodological debate over fixation and staining artifacts divided cell researchers in two polarized groups. Cytologists preferred continuing descriptive research on fixed images of chromosomes and organelles, while general physiologists or "protoplasmologists" sought to develop new physical chemical experiments to study living, uninjured protoplasts. This historical essay shows how the journal Protoplasma emerged from one side of these longer debates over the definition of cellular life, and places the origins of the journal in the context of a changing disciplinary landscape of the life sciences in the first half of the 20th century. It also argues that cross-kingdom research in cell biology has been a foundational source of innovation in cell theory's longer history.