Throughout the Tertiary or Cainozoic Period the dominance of the Angiosperms became more pronounced, and already in the Eocene a flora flourished much resembling in a general way that which now occupies the Earth. Long periods succeeded the Eocene, of which the record is poor so far as plant remains are concerned, at least as regards these countries, but no further great botanical revolutions took place. Through the Miocene Period, with its luxuriant evergreen, subtropical vegetation, we are led to the Pliocene. During this period the climate once again cooled down, and towards the end of it, under conditions very like those prevailing in England at present, many of our familiar species of wild flowers and trees at length made their appearance--Marsh Marigold (_Caltha palustris_), Sloe (_Prunus spinosa_), Blackberry (_Rubus fruticosus_), Hawthorn (_Cratægus Oxyacantha_), Cow Parsnep (_Heracleum Sphondylium_), Bogbean (_Menyanthes trifoliata_), Gypsywort (_Lycopus europæus_), Sheep’s Sorrel (_Rumex Acetosella_), Birch (_Betula alba_), Hazel (_Corylus Avellana_), Oak (_Quercus Robur_), Yew (_Taxus baccata_), Bur-reed (_Sparganium erectum_), Cotton-grass (_Eriophorum polystachion_), Royal Fern (_Osmunda regalis_). The remains of these occur in the “Cromer Forest-bed,” a series of estuarine deposits--laid down perhaps by the ancient Rhine--which underlies the boulder-clay cliffs of the Norfolk coast, and forms almost the only plant-bearing beds of Pliocene Age found in the present land area which we call Britain.