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.

" the marvelous freedom to research what one finds interesting": Theodor Boveri at the Naples Zoological Station.

In January 1888, shortly after his Habilitation (Nov. 1887), Theodor Boveri came for the first time as guest investigator to the Naples Zoological Station. The last of his eight research stays took place in spring 1914, the year before his untimely death in 1915. The Naples Station was therefore a constant presence in all his scientific life. At least 20 of his publications are based on research done at Naples. In this paper, I will try to outline the unique working conditions that Boveri found at Naples. By 1888, the Naples Station was already an expanding, smoothly functioning organism. Excellent animal supply and research equipment, the constant presence of an international scientific community and the beauties of Mediterranean nature and European culture fostered a creative atmosphere that gave particular relevance to a research stay at Naples. In 1910, Boveri defined the Naples Station a "permanent international congress of zoologists". Boveri's "Naples experience" will be described and some light will also be shed on Boveri's role in keeping the memory of Anton Dohrn alive.

Nobel laureates at the Stazione Zoologica Anton Dohrn: phenomenology and paths to discovery in neuroscience.

The practice of science usually involves more than a solitary genius in a solitary room, coping with the problem of her/his life. From the second half of the 19th century onwards, scientific research, especially in the field of the Natural Sciences, has grown into a more and more complex practice, which often entangles very special needs, in terms of research objects, techniques, sources, and perspectives. A few special places, such as the Stazione Zoologica di Napoli, have represented in this period the focal points of an ever growing international scientific network, promoting independent research, exchange and diffusion of novel practices and techniques and unrestricted confrontation. The so-called "Naples experience" has been cited by a large number of renowned scientists of the last two centuries as a key moment in their scientific life. Here we have tried to test it against the experience of three great scientists par excellence, i.e. three Nobel laureates (T. H. Morgan, Otto Warburg, J. D. Watson). The different experiences they have had at Naples represent, in our view, three different moments of the professional life of almost every scientist. Therefore, we have chosen to present them as a phenomenology. The final section is dedicated to a survey of the Zoological Station's contribution to neurosciences, especially to the Naples experience of the Nobel Prize winner Sir Bernard Katz and his assistant Ricardo Miledi, between 1965 and 1970. Their work on the squid at Naples allowed probing and quantitative refinement of results already obtained on different animals and contributed to reinforce the long lasting neurophysiological tradition of the institute.