Drawing made by Lucien Rousseau in the Taillebourg Cave at Roc-aux-Sorciers in 1929. This document is taken from his excavation notebooks, an invaluable source in which Rousseau wrote down all his observations. Excavation is an irreversible act: André Leroi-Gourhan once compared excavation to tearing out the pages of a book once they have been read. What would we know of Rousseau's work if these notes did not exist?