The shingled girl: Catherine Janet Hill and her contributions to embryology

Catherine J. Hill is best remembered for her dedication to cataloguing the comprehensive embryological collection of her father J. P. Hill. Yet, her own research, during the interwar years, is little known. She made a significant contribution to interpreting the autonomic innervation of the gut, work that was presented to The Royal Society and earned her a PhD. Working in her father's laboratory, she then set about solving the sequence of secretions from the tubal epithelium and uterine glands that contributed the two layers of egg albumen and three shell layers of the monotreme egg. She was also the first to understand twinning in the marmoset and how two embryos came to share a single extraembryonic coelom, work that often is credited to J. P. Hill. Here. I explain how that happened and explore the context in which she and other female scientists worked at the time.

Ian Wilmut (1944-2023)

Embryologist who cloned Dolly the sheep.

The people behind the papers - Masaki Kinoshita, Toshihiro Kobayashi, Hiroshi Nagashima, Ramiro Alberio and Austin Smith

The ability to derive and maintain pluripotent stem cells (PSCs) from livestock species in defined media conditions will contribute to many new research avenues, including comparative embryology and xenotransplantation. In a new paper in Development, Masaki Kinoshita, Toshihiro Kobayashi, Hiroshi Nagashima, Ramiro Alberio, Austin Smith and colleagues describe their three-component medium, which supports long-term propagation of PSCs in the absence of feeders or serum factors. We caught up with the authors to find out more about their research and their future plans.

[Modelled Development. Practices of Human Embryology at Göttingen University in the Second Half of the Twentieth Century]

The Human Embryology Collection at the Centre of Anatomy Göttingen, created between 1942 and 1970, represents a unique interrelation of histological sectional series of human embryos and large-format physical models open to the public based on them. The collection was established long after the heyday of human embryology. It is also remarkable in another aspect: while usually models within the discipline are considered research objects, Göttingen embryologist Erich Blechschmidt (1904-1992) based his understanding on a pedagogical impetus. The article highlights the distinctive and unconventional features of Blechschmidt's undertaking against its disciplinary background. My focus lies on the two practices that are central to human embryology-collecting and modelling-, as well as the derived collection stocks. The special tension between individuality and universality that already characterized the process of their creation is also reflected in the later use of the collection. This tension allowed Blechschmidt to utilize the models in embryological research and anatomical teaching as well as in the broad social debate on abortion and the ethical status of human embryos.

Publicity, politics, and professoriate in fin-de-siècle Vienna: The misconduct of the embryologist Samuel Leopold Schenk

This essay uses the case of the fin-de-siècle Vienna embryologist Samuel Leopold Schenk to analyze the factors at play in allegations of misconduct. In 1898, Schenk published a book titled Theorie Schenk. Einfluss auf das Geschlechtsverhältnis (Schenk's theory. Influence on the sex ratio). The book argued that, by changing their diet, women trying to conceive could influence egg maturation and consequently select the sex of their offspring. This cross between a scientific monograph and a popular advice book received enormous publicity but also spurred first the Vienna Medical Association and then the Senate of the University of Vienna to accuse Schenk of poor science, self-advertisement, quack medical practice, and wrong publisher choice. Formal proceedings against Schenk ended in 1900 with the unusually harsh punishment of early retirement. Schenk died two years later. I examine the elements of the case, from the science of sex determination and selection, to the growth of print media and advertising within the changing demographic and political landscape of Vienna. I argue that the influence of the public, via the growing media, upon science was the main driver of the case against Schenk, but also that the case would have had a more limited impact were it not for the volatile political moment rife with anti-Semitism, nationalism, and xenophobia. I draw the attention to the importance of setting cases of misconduct in the broader political history and against the key social concerns of the moment.

An interview with Celina Juliano

Celina Juliano is an Assistant Professor at UC Davis, where she uses Hydra as a model system to understand development and regeneration. She is co-founder of the Cnidarian Model Systems Meeting (Cnidofest) biennial conference and the OpenHydra Hydra resource platform. This year, she was awarded the Elizabeth D. Hay New Investigator award for outstanding developmental biology research during the early stages of her independent career by the Society for Developmental Biology (SDB). Following the virtual SDB 2020 meeting, we met with Celina over Zoom to hear more about her life and career.

The people behind the papers - Kayt Scott and Bruce Appel

In the developing spinal cord, progenitor cells sequentially give rise to motor neurons and precursors of one of the major glial cell types: oligodendrocytes. A new paper in Development unpicks the molecular control of the neuron-glia switch and the differentiation of oligodendrocyte precursors in the zebrafish embryo. To find out more about the work, we met first author and graduate student Kayt Scott and her supervisor Bruce Appel, who holds the Diane G. Wallach Chair of Pediatric Stem Cell Biology and is Professor and Head of the Section of Developmental Biology at the Department of Pediatrics, University of Colorado School of Medicine in Aurora.

The people behind the papers - Xin Zhu, Yiquan Wang and Guang Li

During development, the establishment of directional left-right (L-R) asymmetry is crucial for the correct positioning of organs within the body. How symmetry is broken in the embryo is still incompletely understood at the molecular level, as is its evolutionary history. A new paper in Development tackles this problem with an analysis of L-R asymmetry in the basal chordate amphioxus. We caught up with first author Xin Zhu and supervisors Yiquan Wang and Guang Li of Xiamen University in Fujian, China, to find out more about the work.

The people behind the papers - Charles Sheehan, John McMahon and Debby Silver

Interneurons are crucial to cortical function and their dysregulation has been implicated in various neurological pathologies, yet how they are generated during development is still poorly understood. A new paper in Development investigates interneuron neurogenesis in the mouse embryo and its control by Magoh, a component of the exon junction complex. We heard more about the work from the paper's two first authors, Charles Sheehan and John McMahon, and their supervisor Debby Silver, Associate Professor at Duke University Medical Center in Durham, North Carolina.

An interview with Maria Elena Torres-Padilla

Maria Elena Torres-Padilla is Director of the Institute of Epigenetics and Stem Cells at Helmholtz Zentrum München, Germany. Maria Elena, who studies how cell potency and cell fate are regulated by chromatin-mediated processes, was recently appointed as an Academic Editor at Development. We caught up with Maria Elena at a recent conference to find out more about her background, her research and her thoughts on the ties between the chromatin and developmental biology fields.

A new season for experimental neuroembryology: The mysterious history of Marian Lydia Shorey

At the turn of the nineteenth and twentieth centuries, the landscape of emerging experimental embryology in the United States was dominated by the Canadian Frank Rattray Lillie, who combined his qualities as scientist and director with those of teacher at the University of Chicago. In the context of his research on chick development, he encouraged the young Marian Lydia Shorey to investigate the interactions between the central nervous system and the peripheral structures. The results were published in two papers which marked the beginning of a new branch of embryology, namely neuroembryology. These papers inspired ground-breaking enquiry by Viktor Hamburger which opened a new area of the research by Rita Levi-Montalcini, in turn leading to the discovery of the nerve growth factor, NGF.

The people behind the papers - Maurício Rocha-Martins and Mariana Silveira

Retinal ganglion cells connect the retina to the brain, and their degeneration underlies glaucoma, which is the leading cause of irreversible blindness in humans and currently untreatable. Replacement of lost cells could be achieved by in vivo reprogramming of endogenous cells in the retina, a strategy explored by authors of a new paper in Development who focus on a transcription factor renowned for its reprogramming ability in other contexts. We caught up with first author Maurício Rocha-Martins and his former supervisor Mariana Silveira, Professor at the Federal University of Rio de Janeiro in Brazil, to find out more about the story.

Aristotle vs Galen: Medieval Reception of Ancient Embryology - Medieval Medicine and the 13th Century Controversy over Plurality/Unicity of Substantial Form

In their embryology, Aristotle and Galen greatly disagreed on the role of human derived materials like menstrual blood and vaginal secretion (called by them female sperm or semen). This gap made those two ancients also disagree on their understanding of mother's role in the generation of the human body in her womb. During the Middle Ages, especially during the thirteenth century, the scholastics drew on those two ancient thoughts for some rational underpinnings of their philosophical and theological doctrines. However, the manners of adoption and assimilation were varied. For example, Albert the Great strived to reconcile the two in the image of Avicenna, one of the main and the most important sources of Galenist medicine in the thirteenth Century. By contrast, those scholastics who played an important role in the controversy over plurality/unicity of the substantial form, drew on their disagreements. For example, pluralists like Bonaventure, William of la Mare, and Duns Scotus appealed to Galenist medical perspective to underpin their positions and paved ways to decorate Virgin Mary's motherhood and her active contribution to the Virgin birth and to the manhood of her Holy Son. in contrast a unicist like Thomas Aquinas advanced his theory in line with Aristotelian model that Mary's role in her Son's birth and manhood was passive and material. Giles, another unicist, while repudiating Galenist embryology with the support of Averroes's medical work called Colliget, alluded to some theologically crucial impieties with which might be associated some pluralists' Mariology based on the Roman physician's model. In this processus historiae, we can see not only the intertwining of medieval medicine, philosophy, and theology, but some critical moments where medicine provided, side by side with philosophy, natural settings and explanations for religious marvels or miracles such as the Virgin birth, the motherhood of Mary, the manhood of Christ, etc. Likewise, we can observe two medieval maxims coincide and resonate: "philosophia ancilla theologiae" and "philosophia et medicina duae sorores sunt."

Waddington's epigenetics or the pictorial meetings of development and genetics

In 1956, in his Principles of Embryology, Conrad Hal Waddington explained that the word "epigenetics" should be used to translate and update Wilhelm Roux' German notion of "Entwicklungsmechanik" (1890) to qualify the studies focusing on the mechanisms of development. When Waddington mentioned it in 1956, the notion of epigenetics was not yet popular, as it would become from the 1980s. However, Waddington referred first to the notion in the late 1930s. While his late allusion clearly reveals that Waddington readily associated the notion of epigenetics with the developmental process, in the contemporary uses of the notion this developmental connotation seems to have disappeared. The advent and success of molecular biology have probably contributed to focusing biologists' attention on the "genetic" or the "non-genetic" over the "developmental". In the present paper, I first examine the links that exist, in Waddington's work, between the classical notion of epigenesis in embryology and those of epigenetics that Waddington proposed to connect, and even synthesize, data both from embryology and genetics. Second, I show that Waddington's own view of epigenetics has changed over time and I analyze how these changes appear through his many representations (both schematic or metaphorical images) of the relationships between genetic signals and developmental processes.

An interview with Richard Gardner

Richard Gardner began his career as a PhD student with Bob Edwards and ran his own lab, focusing on patterning of the early mammalian embryo, at the University of Oxford from 1973 until his retirement in 2008. A Fellow of the Royal Society since 1979, he was knighted for services to Biological Sciences in 2005 and received an Honorary Doctorate from Cambridge University in 2012. This year he was awarded the British Society of Developmental Biology (BSDB) Waddington Medal for major contributions to developmental biology in the UK. We caught up with him at the society's Spring Meeting in Warwick and discussed how a book of birds set him on a path to science, how his research was complemented by decades of advising government on scientific policy and why picking the right mentor in research is so important.

Thomas Hunt Morgan and the invisible gene: the right tool for the job

The paper analyzes the early theory building process of Thomas Hunt Morgan (1866-1945) from the 1910s to the 1930s and the introduction of the invisible gene as a main explanatory unit of heredity. Morgan's work marks the transition between two different styles of thought. In the early 1900s, he shifted from an embryological study of the development of the organism to a study of the mechanism of genetic inheritance and gene action. According to his contemporaries as well as to historiography, Morgan separated genetics from embryology, and the gene from the whole organism. Other scholars identified an underlying embryological focus in Morgan's work throughout his career. Our paper aims to clarify the debate by concentrating on Morgan's theory building-characterized by his confidence in the power of experimental methods, and carefully avoiding any ontological commitment towards the gene-and on the continuity of the questions to be addressed by both embryology and genetics.

Crafting socialist embryology: dialectics, aquaculture and the diverging discipline in Maoist China, 1950-1965

In the 1950s, embryology in socialist China underwent a series of changes that adjusted the disciplinary apparatus to suit socialism and the national goal of self-reliance. As the Communist state called on scientists to learn from the Soviets, embryologists' comprehensive view on heredity, which did not contradict Trofim Lysenko (1898-1976)'s doctrines, provided a space for them to advance their discipline. Leading scientists, often trained abroad in the tradition of experimental embryology, rode on the tides of Maoist ideology and repositioned their research. Some of their creative realignment of previous research questions, materials, and traditions to Marxist philosophy and agricultural objectives generated productive programs. In particular, Tong Dizhou (1902-1979) translated Engels's dialectics of nature into a research question about cytoplasmic inheritance. His continuing investigation on it led to the first goldfish "clone" through a nuclear transplantation experiment; Zhu Xi and his associates transferred a goldfish model in embryology into studies on improving carp aquaculture, leading to a rare success in the Great Leap Forward of 1958. These directions for embryology continued well into the 1960s. At a time when global embryology was diversifying and began to be molecularized, eventually forming "developmental biology," socialist embryology took shape in China with a different set of epistemic and practical commitments. The history of its development challenges and enriches our understanding of the concrete process of change in one discipline under Mao, showing ways in which scientists creatively adapted state-sanctioned ideologies and visions to do productive work outside the framework of molecular biology during the Cold War.

Retro reproduction: an old imaging technology rewrites the rules of modern embryology

On a video screen, against a black backdrop, 15 spherical blue-green cells vibrate with a quiet energy. Slowly at first, then faster, they begin to roil and roll. Within the confines of their round membrane cases, they divide, becoming two, three, four cells, then those, in turn, divide to become eight. One splits into two, then pauses, struggling to catch up and spinning off pieces of cellular detritus as it does. Near the top, another, by now many cells rich, hollows out and expands, contracts, expands, contracts. It falls in upon itself and then hatches, pouring out from its shell and ballooning to the side.

Times of danger: embryos, sperm and precarious reproduction ca. 1870s-1910s

This paper discusses the rise and fall of the theory of paternal transmission, drawing attention to the hitherto underresearched debates about the importance and impact of male-mediated harm to the embryo in reproduction that peaked around the turn of the twentieth century. The focus is on the implications of the twin "great social evils," syphilis and alcohol, which converged at the time of a general transformation of medicine into experimental science and a concomitant rise in new concepts of heredity. Looking at the way in which the issue of time added to profound changes which were linked to particular visions of society and changes in the politics of gender at the turn of the century, I examine the asymmetrical relationship of sociopolitical and epistemological dimensions of time and reproduction. The paper shows how these debates were positioned within the wider context of eugenics and in relation to concepts of male reproduction that involved fundamental political, social and moral dimensions.

Traversing birth: continuity and contingency in research on development in nineteenth-century life and human sciences

In the history of life sciences, it has often been argued that the individual organism emerged, around 1800, as a four-dimensional entity--a temporalized entity. Against this backdrop, the article asks how research on development contributed to structuring the time of the organism in terms of a historical process, that is, by understanding a given phenomenon as brought forth by what preceded it and as establishing conditions for what will follow, thus relating the past, the present and the future in a specific way. To shed light on this conceptualization, we must take into account not only embryological research on morphogenesis but also physiological research on the genesis of vital functions and the causation of congenital anomalies. Three layers of structuring time in such research may be discerned: the making of a trans-natal continuity of the developing organism; a conceptualization of birth as a threshold of past and future that paradigmatically reveals the historical understanding of such developmental continuity; and an approach to intergenerational transmission that confronts developmental continuity with historical contingency. My contribution focuses on the work of William T. Preyer and Charles Féré but, in a genealogical vein, situates their work in the larger context of nineteenth-century research on development.

Seeking the constant in what is transient: Karl Ernst von Baer's vision of organic formation

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.

[Caspar Friedrich Wolff: the emergence of epigenesis]

The role of C.F. Wolff, an outstanding anatomist and embryologist, in the development of embryology is described to mark the 280th anniversary of his birth. His life and work were fully elucidated in the book of A.E. Gaisinovich, a famous historian of biology. Although the alternation of preformation and epigenesis is accompanied by a succession of ideas, the boundary between these concepts is clearly retained and depends on many social and cultural factors.

Observing temporal order in living processes: on the role of time in embryology on the cell level in the 1870s and post-2000

The article analyses the role of time in the visual culture of two phases in embryological research: at the end of the nineteenth century, and in the years around 2000. The first case study involves microscopical cytology, the second reproductive genetics. In the 1870s we observe the first of a series of abstractions in research methodology on conception and development, moving from a method propagated as the observation of the "real" living object to the production of stained and fixated objects that are then aligned in temporal order. This process of abstraction ultimately fosters a dissociation between space and time in the research phenomenon, which after 2000 is problematized and explicitly tackled in embryology. Mass data computing made it possible partially to re-include temporal complexity in reproductive genetics in certain, though not all, fields of reproductive genetics. Here research question, instrument and modelling interact in ways that produce very different temporal relationships. Specifically, this article suggests that the different techniques in the late nineteenth century and around 2000 were employed in order to align the time of the researcher with that of the phenomenon and to economize the researcher's work in interaction with the research material's own temporal challenges.

Folding into being: early embryology and the epistemology of rhythm

Historians have often described embryology and concepts of development in the period around 1800 in terms of "temporalization" or "dynamization". This paper, in contrast, argues that a central epistemological category in the period was "rhythm", which played a major role in the establishment of the emerging discipline of biology. I show that Caspar Friedrich Wolff's epigenetic theory of development was based on a rhythmical notion, namely the hypothesis that organic development occurs as a series of ordered rhythmical repetitions and variations. Presenting Christian Heinrich Pander's and Karl Ernst von Baer's theory of germ layers, I argue that Pander and Baer regarded folding as an organizing principle of ontogenesis, and that the principle's explanatory power stems from their understanding of folding as a rhythmical figuration. In a brief discussion of the notion of rhythm in contemporary music theory, I identify an underlying physiological epistemology in the new musical concept of rhythm around 1800. The paper closes with a more general discussion of the relationship between the rhythmic episteme, conceptions of life, and aesthetic theory at the end of the eighteenth century.

An appreciation of Christiane Groehen: the correspondence between Charles Darwin and Anton Dohrn

Anton Dohrn was introduced to Darwinism by Ernst Haeckel during his student years at Jena, and became an eager disciple of Charles Darwin's work. He founded the Stazione Zoologica in 1872. Darwin became a patron of Dohrn's Stazione, and the two naturalists corresponded regularly. This article discusses their relationship and the contributions of Christiane Groeben to its elucidation.

The Marine Biological Laboratory (Woods Hole) and the scientific advancement of women in the early 20th century: the example of Mary Jane Hogue (1883-1962)

The Marine Biological Laboratory (MBL) in Woods Hole, MA provided opportunities for women to conduct research in the late 19th and early 20th century at a time when many barriers existed to their pursuit of a scientific career. One woman who benefited from the welcoming environment at the MBL was Mary Jane Hogue. Her remarkable career as an experimental biologist spanned over 55 years. Hogue was born into a Quaker family in 1883 and received her undergraduate degree from Goucher College. She went to Germany to obtain an advanced degree, and her research at the University of Würzburg with Theodor Boveri resulted in her Ph.D. (1909). Although her research interests included experimental embryology, and the use of tissue culture to study a variety of cell types, she is considered foremost a protozoologist. Her extraordinary demonstration of chromidia (multiple fission) in the life history of a new species of Flabellula associated with diseased oyster beds is as important as it is ignored. We discuss Hogue's career path and her science to highlight the importance of an informal network of teachers, research advisors, and other women scientists at the MBL all of whom contributed to her success as a woman scientist.

[Embryology and "official science": the contribution of the anatomical school of José Escolar to embryology during the first Francoism (1939-1959)]

In this paper, we analyse the contribution of the anatomical school of José Escolar (1913-1998) to embryology during the first two decades of the Francoist dictatorship. Special attention is paid to the process by which the Spanish group, with the support of the new Superior National Research Council, made contact with the German morphology being developed by Hugo Spatz (1888-1979) at the Max Planck-Institut für Hirnforschung. Our study reveals the numerous influences that finally led to the anatomy and embryology of Escolar. In Spain, we found a direct influence of the Gegenbaurian morphology of Gumersindo Sánchez Guisande (1894-1976) and the neuroanatomy of Juan José Barcia Goyanes (1901-2003), full of references to studies by Braus. International contacts of the "Escolarian group", first with North America and then with Germany, created a homogeneous group with a single anatomy (functional and ontophylogenetic) but with so many research interests that subspecialisations had to be developed. An important embryological work resulted from an intense relationship with the German anatomical community during the 1950s. Escolar worked in this field on the development of the amygdala and allocortex, Fernando Reinoso studied the embryology of the diencephalon and Smith Victor Agreda, along with the German scientist Rudolf Diepen, made some important discoveries on the development of the hypothalamic-pituitary system.

Plato's Embryology

Embryology was a subject that inspired great cross-disciplinary discussion in antiquity, and Plato's Timaeus made an important contribution to this discussion, though Plato's precise views have remained a matter of controversy, especially regarding three key questions pertaining to the generation and nature of the seed: whether there is a female seed; what the nature of seed is; and whether the seed contains a preformed human being. In this paper I argue that Plato's positions on these three issues can be adequately determined, even if some other aspects of his theory cannot. In particular, it is argued that (i) Plato subscribes to the encephalo-myelogenic theory of seed, though he places particular emphasis on the soul being the true seed; (ii) Plato is a two-seed theorist, yet the female seed appears to make no contribution to reproduction; and (iii) Plato cannot be an advocate of preformationism.

[The scientific works of the teachers of human anatomy in the "Université Libre de Bruxelles" (ULB)]

The "Université Libre de Bruxelles" was founded in 1834. Between this year and 1904, the teachers of human anatomy were essentially clinicians and surgeons. Their works were mainly practical. Until 1904 (arrival of Albert Brachet) since present, the researches of the anatomical laboratory were devoted to embryology, and included the beginning of causal embryology. More recently, biomechanics appeared in the field of activity of the laboratory.

["The first stages of the human egg" by Auguste d'Eternod published one hundred years ago in the Comptes Rendus de l'Association des Anatomistes]

The development of the embryo and foetus fascinates, but its study in humans is difficult because of both technical and ethical problems. Auguste d'Eternod, Swiss embryologist, published in 1913 an article entitled "The early stages of the human egg" in the Comptes Rendus de l'Association des Anatomistes, the ancestor of the journal Morphologie. This work is focused not only on the early stages of development: fertilization, cleavage of the egg, blastocyst formation, gastrulation, but also on the extra-embryonic processes characteristic of mammals. On the occasion of the centenary of the publication of this work, I propose a critical review by placing the data published in the literature and historical context of the time. Finally, I try to extract from these observations the concepts that are still used today by embryologists.

[On a contribution of Boris Balinsky to the comparative and ecological embryology of amphibians]

The outstanding embryologist Boris Ivanovich Balinsky (1905-1997) worked in the Soviet Union up to 1941 and in South Africa since 1949. His experimental studies fulfilled during the Soviet period of his scientific career mainly on the embryos of the caudate amphibians are widely known. After moving to Africa (Johannesburg), he continued the research of amphibian development, with using those possibilities, which were offered by the diverse fauna of local Anura. Other embryologists started complex studies of tropical frog ontogenies (mainly from South and Central America) 30-40 years later than Balinsky. Unfortunately, his pioneering works on numerous African species are poorly known (with the exceptions of the description of the development of endodermal derivatives in Xenopus laevis and the analysis of limb induction in the toad genus Amietophrynus). In this paper, the works of Balinsky are analyzed (with the emphasis on comparative and ecological aspects) and his priority in using of "nonmodel" tropical and subtropical anurans in embryological studies has been shown.

Pre-modern Islamic medical ethics and Graeco-Islamic-Jewish embryology

This article examines the, hitherto comparatively unexplored, reception of Greek embryology by medieval Muslim jurists. The article elaborates on the views attributed to Hippocrates (d. ca. 375 BC), which received attention from both Muslim physicians, such as Avicenna (d. 1037), and their Jewish peers living in the Muslim world including Ibn Jumay' (d. ca. 1198) and Moses Maimonides (d. 1204). The religio-ethical implications of these Graeco-Islamic-Jewish embryological views were fathomed out by the two medieval Muslim jurists Shihāb al-Dīn al-Qarāfī (d. 1285) and Ibn al-Qayyim (d. 1350). By putting these medieval religio-ethical discussions into the limelight, the article aims to argue for a two-pronged thesis. Firstly, pre-modern medical ethics did exist in the Islamic tradition and available evidence shows that this field had a multidisciplinary character where the Islamic scriptures and the Graeco-Islamic-Jewish medical legacy were highly intertwined. This information problematizes the postulate claiming that medieval Muslim jurists were hostile to the so-called 'ancient sciences'. Secondly, these medieval religio-ethical discussions remain playing a significant role in shaping the nascent field of contemporary Islamic bioethics. However, examining the exact character and scope of this role still requires further academic ventures.

The Demise of the Preformed Embryo: Edinburgh, Leiden, and the Physician-Poet Mark Akenside's Contribution to Re-Establishing Epigenetic Embryology

Seventeenth-century advances in microscopy prompted a shift in the dominant theory of human reproduction from one of epigenesis, derived from such ancient authorities as Aristotle, which posited that the mixing of male and female reproductive material generated a being which had not existed before, to one of preformation, whereby embryologists argued that the offspring of an animal already existed in miniature in the reproductive material. This chapter reveals that the poet, Mark Akenside, anticipated the Enlightenment's challenge to the prevailing preformationist orthodoxy when a medical student at Edinburgh in the late 1730s, as evident in his May 1744 thesis entitled De ortu et incremento foetus humani ('On the Origin and Growth of the Human Foetus'). What prompted Akenside to take such a bold step? Faced with a scarcity of biographical sources, Akenside's major poem on The Pleasures of Imagination (1744) suggests how the poet had been thinking about reproductive processes in innovative contexts and that his medical research informed his concept of poetic creation.

[Scientific revolution and embryology: rejection or transformation of antiquity? A comparison between the procreation teachings of Cesare Cremonini, William Harvey und René Descartes]

In this paper I address the issue of the theoretical and epistemological status of embryology at the rise of the so-called "Scientific Revolution" (also in the first half of the seventeenth-century) and raise the question, in what sense and to what extent the historiographical concept of "Scientific Revolution" is applicable to the domain of embryology. To achieve this aim I compare the theories of three protagonists of the medical, scientific and philosophical debate of that age, namely Cesare Cremonini, William Harvey and René Descartes, who had very different views on the world structure and human nature and a very different concept of science, but who shared, as concerns embryological issues, an epigenetic conception of the development of the embryo. Their theories are discussed and compared in light of following questions: 1) What do Cremonini's, Harvey's and Descartes's embryological theories exactly aim to?; 2) In developing their theories, do these thinkers deal explicitly or implicitly with the Aristotelian and the Galenic embryological paradigm?; 3)Do they refer polemically to the Aristotelian and the Galenic tradition and what theoretical and/or rhetorical function have these polemical references?; 4) Do the embryological theories of Cremonini, Harvey and Descartes reflect the century-long dispute between "(Aristotelian) philosophers" and "(Galenic) doctors"?; 5) How is represented embryology as a 'scientific' and/or 'theoretical' domain? And what relationship between concepts of 'truth', 'research', 'tradition' and 'scientific progress' is implied or proposed in the embryological works of these three thinkers? What kind of use do Cremonini, Harvey and Descartes make of the argumenta ex ratione and of those ex experientia?