This is a slug in a bottle.
To be more specific, it’s “Illustrations of the experiments of H. Regius to prove the circulation of the animal spirits in the slug. Slug in flask.”
The picture’s from the Philosophia naturalis of H. Regius. T – the “H” is short for “Henricus”; he was a Dutch medical researcher and colleague of Descartes who ignited some controversies in his lifetime – mostly to do with the nature of the soul, of the mind and of life itself, moreso than putting slugs in bottles. But all that stuff was related.
I found the image in the Wellcome Collection woodcuts on Wikimedia Commons.