Organisms as Russian dolls

The findings of early microscopists such as Malpighi and Swammerdam were sometimes taken to support the preformationist theories of thinkers such as Malebranche. Here, we look in some more detail at the connection between preformationist biology and the findings of the early microscopists.

What biologists such as Swammerdam saw under their microscopes, was that the complex organic structure of many animals was there well before it could be discerned by the naked eye. Thus Swammerdam argued that the limbs and wings of a butterfly were already present, albeit folded up, underneath the skin of a caterpillar. If these limbs and wings could not be discerned with the naked eye, the microscope helped to discover them. As he put it Historia insectorum of 1669:

The caterpillar is the butterfly itself, but as it were covered in a robe that prevents its parts from making themselves known. (Historia insectorum, Part II:45)

Illustration from Swammerdam’s 1669 Historia insectorum

We ought to accept, in addition, that the body of every man and beast born till the end of time was perhaps produced at the creation of the world. My thought is that the females of the original animals may have been created along with all those of the same species that they have begotten and that are begotten in the future. (The Search for Truth, 27. Translation Lennon and Olscamp)