This article is about the beginnings of tissue culture-the culture of living, reproducing cells of complex organisms outside the body. It argues that Ross Harrison's experiments in nerve culture between 1907 and 1910 should be viewed as part of a larger shift in early twentieth-century laboratory practice from in vivo to in vitro experimentation. Via a focus on the temporality of experiment-contrasting the live object of Harrison's investigation with the static object of histological representations-this article details the production of a (...) new and surprising form of life, cellular life in vitro. Tissue culture, developed from Harrison's experiments, was greeted with great surprise and disbelief, despite Harrison's protestations that he had merely juxtaposed extant techniques. An analysis of these initial reactions to tissue culture illuminates the extent to which cells living visibly outside of the body in glass broke with in vivo practices and assumptions of the hiddenness and interiority of certain processes of growth and change. (shrink)

The invisible object, in the eighteenth century, is not an evidence. It is the result of textual and semantic learning. Which concrete strategies are used to construct and depict objects out of sight? How do we make them a cognitive reality acceptable to a scientific community? This paper first highlights the conditions for the emergence of a field of microscopic knowledge and its epistemological consequences. Then we consider the microscopic gaze in terms of learning, situated between the act of observation (...) as such and discursive practices. We conclude by studying a concrete case of “negotiation of the invisible” in a correspondence between Carl Linnaeus and John Ellis concerning corpuscles observed in mushroom infusions. (shrink)

The cell is not only the structural, physiological, and developmental unit of life, but also the reproductive one. So far, however, this aspect of the cell has received little attention from historians and philosophers of biology. I will argue that cell theory had far-reaching consequences for how biologists conceptualized the reproductive relationships between germs and adult organisms. Cell theory, as formulated by Theodor Schwann in 1839, implied that this relationship was a specific and lawful one, that is, that germs of (...) a certain kind, all else being equal, would produce adult organisms of the same kind, and vice versa. Questions of preformation and epigenesis took on a new meaning under this presupposition. The question then became one of whether cells could be considered as autonomous agents producing adult organisms of a given species, or whether they were the product of external, organizing forces and thus only a stage in the development of the whole organism. This question became an important issue for nineteenth-century biology. As I will demonstrate, it was the view of cells as autonomous agents which helped both Charles Darwin and Gregor Mendel to think of inheritance as a lawful process. (shrink)

A well-established narrative in the history of science has it that the years around 1800 saw the end of a purely descriptive, classificatory and static natural history. The emergence of a temporal understanding of nature and the new developmental-history approach, it is thought, permitted the formation of modern biology. This paper questions that historical narrative by closely analysing the concepts of development, history and time set out in Karl Ernst von Baer’s study of the mammalian egg (1827). I show that (...) Baer’s research on embryogenesis aimed not simply to explain temporal changes, but to inscribe the formation of new individual organisms into a continuous, unending organic process. I confront Baer’s views with other explanations of embryogenesis arising in the 1820s and 1830s, especially those of Jean-Baptiste Dumas and Jean-Louis Prévost and of Theodor Schwann. By highlighting divergences between these scientists, especially as to their view of the role of gender differences in reproduction, I argue that biology evolved not from a homogeneous concept of developmental history but out of various, even opposing, views and research programmes. Thus, the birth of biology did not imply the end of all natural history’s thought models. (shrink)