On the occasion of the fourth centenary of the birth of Federico Cesi, the Committee nominated by the Academy of the Lincei for the celebrations, sent a cultural mission to Paris to get direct knowledge of the mycological codes of the Lincei, today preserved in the library of the Institut de France. In reality one took note of a much vaster quantity of material than one had predicted: not only three codes of funghi, but also eight volumes in-folio that represent the Syntaxis plantaria of Federico Cesi. The roughly 1900 representations of plants, mostly in colour, are enriched by autographic notes of the linceo Prince, and witness the systematic use of the microscope as the instrument of scientific research. Consequently it underlines the necessity of a more profound study of these materials, extremely interesting for the history of the science; at the same time one hopes that one can realise the publication together with the reedition of the Tabulae phytosophicae, of which they represent the natural complement.