Producing Development: The Anatomy of Human Embryos and the Norms of Wilhelm His

In 1875 the Göttingen anatomist Wilhelm Krause described what was briefly the most famous but soon became the most notorious human embryo of the last quarter of the nineteenth century. It was presented as deciding a heated controversy over embryology and evolution, but its status was debated in dozens of publications--until in 1882 anatomists finally agreed that it was the embryo, not of a human being at all, but of a bird. I shall reconstruct the remarkable history of Krause's embryo, but my larger concern is with the enterprise to which it fell victim: the making of modern human embryology. This was the achievement, above [Begin Page 31] all, of the Leipzig anatomist Wilhelm His (1831-1904), whose Anatomie menschlicher Embryonen (Anatomy of human embryos) dramatically reformed the field. ¹ The most important part of this work was a series of standard drawings of developing embryos advancing from the end of the second week to the end of the second month of pregnancy (Fig. 1). Development is usually taken for granted as what embryologists study; here, by analyzing the practical activities through which His constructed these norms, I investigate development as an effect that he labored to produce. Further, this article contributes to three historical literatures. First, studying a work conspicuously absent from recent historical writing on human embryos shows how and why His created human embryology as it would be practiced through the twentieth century. Second, highlighting this new human embryology restores a missing dimension to our picture of the transformation of the life and medical sciences between the post-Darwinian controversies and World War I. And third, analyzing closely the making of a particular atlas extends our understanding of this key genre of scientific standards.

Embryologists' major products have been developmental series: successions of progressively more advanced embryos, in the form variously of drawings, specimens in spirits, models, photographs, posters, sonograms, videos, and flip-charts. All work in embryology has depended on, and most has in its turn generated, these material representations of development. The representation of developing embryos has constituted the science by producing objects that embryologists could manipulate; displaying such series has communicated development widely. Yet historians of embryology have traditionally taken this labor for granted. Subordinating practical activities to theories of development, they have given us a history of concepts and problems with only perfunctory nods toward technique. ² In particular, historians of science have emulated those embryologists who, defining their own practice as "experimental," have since the late nineteenth century marginalized work considered merely descriptive of stages of development. ³ It is high time, by contrast, to follow those sociologists and historians who have paid attention to the mundane practices and material cultures of other medical and biological sciences, and to take the most routine work of embryology seriously. ⁴ Analyzing the construction of developmental series can demonstrate how by making, selecting, and ordering embryonic images, embryologists have materially produced development. Explaining the distribution of the most basic and widely important products of the science can account for the triumph of the embryological view of life and show how our own embryo-laden world was made.

A key work of human embryology will serve as an example. The extreme challenge of making developmental series for the relatively complex and inaccessible human embryos helps to make taken-for-granted practices explicit. And, as a routine part of the experience of monitored childbirth in the industrialized world, ⁵ and a potent means through which, over the last few decades, the politics of reproduction have been fought out, ⁶ human embryonic and fetal images are attracting intense interest. Greater historical consciousness would enrich present debates. For though today series of developing human embryos are the dominant representations of pregnancy, they have been made for only the last two hundred years. Until...