72 



Origin of the British Flora. 



The cuttings for the North Sea Canal showed silted-up 

 channels with Pleistocene plants. One at Beldorf exposed 

 a trough cut in the boulder-clay, filled with deposits yielding 

 temperate plants, at the top of which occurred a layer with 

 Betula nana, the whole being levelled up and hidden by 

 recent peat. This intercalation of a temperate flora be- 

 tween the boulder-clay and an Arctic plant-bed agrees 

 with the succession found at Hoxne in Suffolk. Another 

 channel at Grossen-Bornholt is apparently of the same 

 date. The plants occur in several different beds, full 

 details being given in Dr. Weber's papers. 



Ranunculus. 

 Nuphar luteum. 

 Nymphrea alba. 

 Brasenia purpurea. 

 Tilia platyphyllos. 

 Ilex aquifolium. 

 Acer. 



Prunus Avium. 

 Hippurus vulgaris. 

 Myriophyllum spicatum. 

 Trapa natans. 

 Galium uliginosum. 

 Vaccinium Vitis-Idaea. 



Myrtillus. 



Andromeda Polifolia. 

 Fraxinus excelsior (?). 

 Menyanthes trifoliata. 

 Betula alba. 



Alnus glutinosa. 

 Carpinus Betulus. 

 Corylus Aveilana. 

 Ouercus Robur. 

 Salix pentandra (?). 



Caprea. 



Ceratophyllum demersum. 



Juniperus communis. 



Picea excelsa. 



Pinus sylvestris. 



Stratiotes aloides. 



Typha. 



Potamogeton natans. 



Najas flexilis. 



Eriophorum. 



Carex panicea. 



Holcus. 



Phraemites. 



nana. 



Hailes, near Edinburgh. 



(J. Geikie, 'Great Ice Age,' 3rd edit., p. 99. 1894; 

 Bennie, ' Arctic Plants in the old Lake Deposits of Scot- 

 land,' Ann. Scottish Nat. Hist., 1894, pp. 46-5 2.) 



Two plant-bearing deposits are found at this spot. 

 The lower one rests immediately on the Boulder Clay and 



