From exceptional to common presence: Italian women in twentieth-century life sciences.

This essay surveys the situation of Italian women life scientists from the late nineteenth to the mid-twentieth century. It follows the path that took women from being an exceptional presence to becoming a common, yet not equal, presence in the Italian science departments. Very different proportions of women occupied the three ranks in the academic hierarchy-students, research staff and professors. From the late nineteenth century onwards, women started to enrol in Italian universities. Initially, the second most popular department among female students-outdone only by the humanities-was that of mathematics, physics and natural sciences. Concerning women among research staff, a brief statistical analysis reveals the growing proportion of the female workforce in academic institutions and brings into view poorly known female assistants and technicians. The most difficult career step for women was to gain a tenured university position. A comparison between bacteriologist Giuseppina Cattani's 'failure' to gain such a position and the ultimately successful strategy of zoologist and limnologist Rina Monti, who became one of the very first female university professors in Europe, illustrates the opportunities as well as the obstacles women naturalists encountered on the way into the academia. These experiences and those of others show that well into the twentieth century the support of powerful male mentors continued to be indispensable for women scientists. Positions in peripheral institutes or specializations in emerging research fields, in particular hydrobiology, entomology and cytogenetics, provided opportunities for Italian women to work their way up to professorships.

Cycles and circulation: a theme in the history of biology and medicine.

We invite systematic consideration of the metaphors of cycles and circulation as a long-term theme in the history of the life and environmental sciences and medicine. Ubiquitous in ancient religious and philosophical traditions, especially in representing the seasons and the motions of celestial bodies, circles once symbolized perfection. Over the centuries cyclic images in western medicine, natural philosophy, natural history and eventually biology gained independence from cosmology and theology and came to depend less on strictly circular forms. As potent 'canonical icons', cycles also interacted with representations of linear and irreversible change, including arrows, arcs, scales, series and trees, as in theories of the Earth and of evolution. In modern times life cycles and reproductive cycles have often been held to characterize life, in some cases especially female life, while human efforts selectively to foster and disrupt these cycles have harnessed their productivity in medicine and agriculture. But strong cyclic metaphors have continued to link physiology and climatology, medicine and economics, and biology and manufacturing, notably through the relations between land, food and population. From the grand nineteenth-century transformations of matter to systems ecology, the circulation of molecules through organic and inorganic compartments has posed the problem of maintaining identity in the face of flux and highlights the seductive ability of cyclic schemes to imply closure where no original state was in fact restored. More concerted attention to cycles and circulation will enrich analyses of the power of metaphors to naturalize understandings of life and their shaping by practical interests and political imaginations.

Pioneering Studies on Cephalopod's Eye and Vision at the Stazione Zoologica Anton Dohrn (1883-1977).

From the late nineteenth century onwards, the phenomena of vision and the anatomy and physiology of the eye of marine animals induced many zoologists, ethologists, physiologists, anatomists, biochemists, and ophthalmologists to travel to the Zoological Station in Naples. Initially, their preferred research objects were fish, but it soon became evident that cephalopods have features which make them particularly suited to research. After the first studies, which outlined the anatomical structure of cephalopods' eyes and optic nerves, the research rapidly shifted to the electrophysiology and biochemistry of vision. In the twentieth century these results were integrated with behavioral tests and training techniques. Between 1909 and 1913 also the well-known debate on color vision between ophthalmologist Carl von Hess and zoologist Karl von Frisch took place in Naples. Largely unknown is that the debate also concerned cephalopods. A comparative historical analysis of these studies shows how different experimental devices, theoretical frameworks, and personal factors gave rise to two diametrically opposing views.

Of germ-plasm and zymoplasm: August Weismann, Carlo Emery and the debate about the transmission of acquired characteristics.

In this essay I discuss the contents and the context of Italian zoologist and entomologist Carlo Emery's discussion of the germ-plasm theory. August Weismann considered him one of his very few creditable supporters, and encouraged him to publish his theoretical reflections. In his Gedanken zur Descendenz- und Vererbungstheorie, which appeared between 1893 and 1903 as a series of five essays in the journal Biologisches Zentralblatt, Emery developed a very personal account, applying the concept of determinants to problems like atavism, sexual dimorphism, speciation, geographical isolation, transmission of characters, and putting forward, as early as 1903, the idea of a genetic program.

Images of cell trees, cell lines, and cell fates: the legacy of Ernst Haeckel and August Weismann in stem cell research.

Stem cells did not become a proper research object until the 1960 s. Yet the term and the basic mind-set--namely the conception of single undifferentiated cells, be they embryonic or adult, as the basic units responsible for a directed process of development, differentiation and increasing specialisation--were already in place at the end of the nineteenth century and then transmitted on a non-linear path in the form of tropes and diagrams. Ernst Haeckel and August Weismann played a special role in this story. The first coined the term Stammzelle (stem cell), the second was the author of the first cellular stem-tree diagram. Even today, I shall argue, the understanding of stem cells, especially the popular perception, is to a large extent a Haeckelian-Weismannian one. After having demonstrated this, by analysing the terminology, in this essay I will focus on the use of cytogenetic tree diagrams between 1892 and 1925 and on the tacit understanding of stem cells that they transmit.

Cellular dimensions and cell dynamics, or the difficulty over capturing time and space in the era of electron microscopy.

The introduction of electron microscopy profoundly altered biomedical research, providing a tool for a more detailed but at the same time a spatially and temporally more restricted visual analysis. Examining the case study of Golgi apparatus research in the 1950s and 1960s, it will be shown how microscopists handled these challenges, and how these confrontations modified the general concept of cellular organization. This will also shed light on the artifact debate and on the question of scientific realism in the field of microscopy.

Edmund B. Wilson's the cell and cell theory between 1896 and 1925.

Edmund Beecher Wilson is generally celebrated for his contribution to chromosome theory and genetics, whereas opinion concerning his cytological thinking is often restricted to the idea that he provided evidence for the dominant role of the nucleus. But Wilson's cell theory was much more. It was a child of the German Zellforschung, and its attempt to provide a comprehensive cellular answer to a wide range of biological and physiological questions. Wilson developed a corpuscular, micromeristic and preformistic concept, and treated the cell as an organism subject to ontogenetic and phylogenetic processes. He defended his comprehensive theory even in the 1920's, when cytological research had become specialised and directed at more practical goals. For many of his younger readers this concept might have seemed antiquated, but today many of its features sound surprisingly modern.