skip to content

Accurate formal representation of frogs was of central importance to 19th century anatomists and their artisan collaborators. Different types of observing and modelling demanded different sorts of expertise from all involved, and transformed the purposes of studios like Ziegler's along with their relation to academic patrons.

The primordial skulls seen here are in fact models of models. Work was often performed within the universities by researchers or technicians who would then send their models to Ziegler for 'publication'. By the 1880s, Ziegler's studio was receiving many such models from all over Germany. University researchers, including Stöhr, who produced the original models for these primordial skulls, had then begun to use a new technique. They built section-based models of embryos using microtomes, which would cut extremely thin slices off a specimen. The modeller would then project and trace those sections onto a thin layer of wax before cutting that section out. Multiple wax sections would then be stacked into a three-dimensional model.

Models of frog, salmon and axolotl 'primordial skulls' during embryonic development.
Models of frog, salmon, and axolotl 'Primordial' skulls during embryonic development by Adolf Ziegler, circa 1881 (Wh.6401, Wh.6402 and Wh.6403).

Since the technical work of modelling now took place in only two dimensions, and therefore required far less skill, researchers began to issue such work to laboratory technicians. Ziegler's role consisted in processing those stacks of two-dimensional plates, refining their distortions, and reproducing them as beautiful, vivid objects for sale. These 'Primordial Skull' models are the outcome of such a process.

The Ziegler Models have attracted much scholarly attention within our own department. When you visit the Whipple Museum, look for our Main Gallery display curated by Prof. Nick Hopwood, 'Embryos in Wax.' You can also ask our gallery attendant to show you his book, Embryos in Wax: Models from the Ziegler studio (published by the Museum in 2002), to see his expert analysis of these specimens alongside rich images of Ziegler's whole 'library' of models.

Henry Schmidt

Henry Schmidt, 'Techniques of observing and modelling', Explore Whipple Collections, Whipple Museum of the History of Science, University of Cambridge.

Next Article: Frogs in the Classroom

Opening Times

Please note that we are closed for Bank Holiday Monday, 27th May

We are open five days a week, 12.30 - 16:30.

Monday 12.30 - 16:30

Tuesday 12.30 - 16:30

Wednesday 12.30 - 16:30

Thursday 12.30 - 16:30

Friday 12.30 - 16:30

We hope to see you soon!