Enkele opmerkingen over het verband tussen het Rijngedeelte van het Fluviatiele district en het Duindistrict

The author discusses the possibility that part of the river Rhine formerly flowed into the Northsea near Egmond (province of Noord-Holland). At that time the flora of the Dune District had a rather close relationship with that of the Fluviatile District, as is shown by a number of shared plant species.