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inner side of our dunes, in places where an ancient 

 river-bed of the Rhine may hâve existed. Further I only 

 know from a station near Darmstadt (on the Rhine!) and 

 one or two other places. Could this Geaster therefore 

 perhaps be a link of our argumentation in favour of 

 Prestwitch es.? Another point, which struck me with 

 Van Eeden, is that speaking about the présence of 

 Rhine-plants near Harlem he also refers to a connection 

 with England, without knowing however anything about 

 the view of Prestwitch, Harmer etc. On the well- 

 known country-seat Duin en Kruidberg to the north of 

 Harlem Viburnum Lantana L. is found growing wild. In our 

 country this plant is further only found in the south of Lim- 

 burg. In Belgium it occurs in the east part only, in Germany 

 not in the northern districts, Saxonia and Silesia, but not 

 even rarely in the centre and the south-west. Reasons 

 enough to suppose, that we hâve got to do hère with a 

 true river-plant, and to consider its présence north of 

 Harlem as an argument in support of the theory, that 

 once the Rhine has passed hère. This opinion is shared 

 indeed by Van Eeden, who at the same time men- 

 tions, that this species also occurs on the opposite coast- 

 regions of England, which according to him points to a 

 connection between England and HoUand. It is only to 

 be regretted, that our Viburnum may by suspected to 

 hâve been spreé^d by birds ! But perhaps in the times of 

 Van Eeden it was not yet so intensively cultivated, 

 that it was necessary to think of this possibility? Primula 

 acaulis Jcq. also is mentioned by Van Eeden as a plant, 

 which, being common on the inner side of our dunes and 

 on the opposite side of the North Sea, as well as in 

 Germany and Switzerland, whilst in Belgium it only occurs 

 naturalized in a few places, may point to an ancient river-bed 

 of the Rhine; but unfortunately this species also is suspected 

 to be in our country only as the resuit of former cultures. 



