The evolution of wood ring in Castanea sativa mill. — The Author has studied the wood ring evolution during one year on two specimens ofCastanea sativaMill. growing respectively the former in a chestnut wood at Masso del Diavolo (ca 1000 m. over sea level), near Vallombrosa, a locality lying outside the normal area of distribution of the species, and the latter at Colle di S. Giusto (ca 500 m. over sea level), near Greve, a locality included in the «horizon» proper of the species. In the former contemporary wood growth of the main stem, branch and sterile shoot has been studied; in the latter wood growth of the stem and the branch only.