There is much to learn from Janina Wellmann's book, which is a translation of Die Form des Werdens: eine Kulturgeschichte der Embryologie 1760–1830 (2010). The “cultural history” in question does not just have to do with early embryological theory, but rather—and even more so—with a word absent from the original German title: rhythm. The idea of rhythm is central to the entire project and, in particular, informs the readings of the first six chapters, with their focus on literature (including Klopstock, Hölderlin, Moritz, Novalis, and A. W. Schlegel), late eighteenth-century music theory, Schelling's Naturphilosophie and Philosophie der Kunst, and various aspects of “biological rhythm” (Wolff, Goethe, Reil). As Wellmann points out in her introduction, we lack a history of the concept of rhythm and, with the exception of more etymologically grounded studies, “there has been practically no research on the cultural and scientific history of rhythm before 1900” (19). Rhythm's connection to embryology lies, as Wellmann understands it, in the problem of “developmental thinking” around 1800: how to conceptualize the “form of becoming” in living nature and the activities of human culture. More concretely, it could be formulated as the question of how an organism could “continually change, yet still be ordered”: “How could the parts combine into a highly complex formation when they themselves were all changing as incessantly as did the whole?” (16).

Wellmann begins with the premise that such questions are equally valid in aesthetic and biological terms. Each of her subsequent arguments centers around the general claim that a new “episteme of rhythm” was established around 1800 whereby, in numerous fields of human inquiry, the idea of change over time was understood as “rhythmical”: “Rhythm described the emergence and formation of life not as a mere progression in time, but as an ordering of time” (17). Wellmann identifies her own approach as a kind of expanded “history of concepts” that also considers methods and questions from various fields, including cultural history, visual studies, and the history of science.