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the periodical : "Het album der natuur" (The album of 

 nature), which unfortunately has ceased toappear. At présent 

 many persons, especially botanists, believe in such a course, 

 but in the times of Van Eeden the idea was new. I hâve 

 not become any the wiser by it. Van Eeden records as 

 typical Rhine-plants of the environs of Harlem Epilobium 

 hirsutum L., Plantago média L., Euphorbia Cyparissias L. 

 var. fi esuloides D, C, Sedum purpurascens Koch, further 

 Adoxa Moschatellina L., Aristolochia Clematitis L, ^naWy 

 two plants of the ruins of Brederode, namely Cheiranthus 

 Cheiri L. and Parietaria erecta M. et K. Ail thèse plants are 

 found growing wild in Switzerland, the last three not often. In 

 Belgium the first five are widely spread, though chiefly 

 in the east part ; the last three are considered to hâve 

 been introduced and in our country also hâve perhaps 

 only escaped from castle- and cloister-gardens ; the last 

 two only grow on walls, like in our country. In Germany 

 also the first five of the above-mentioned species are 

 widely spread ; the Aristolochia grows wild in a part of 

 it (perhaps in Alsatia and Baden ?), but is considered else- 

 where to be naturalized, like the Parietaria and the 

 Cheiranthus; the latter seems to be conflned to the west 

 part (the river-basin of the Rhine?). It will not be possible 

 to prove much by means of ail thèse plants. They may 

 hâve a local importance, but to our problem they are 

 not of any great value. There are, however, a few points, 

 which struck me particularly when reading the works of 

 Van Eeden. This was the case in the first place with 

 the distribution of a very remarkable mushroom, the 

 Geaster coîiformis Dicks. It was discovered in England by 

 Sowerby and in this country only occurs in grassland 

 on sandy soil of Norfolk and Suffolk. In 1865 it was 

 found for the first time in our country (by Hugo de 

 Vries, near Katwijk on the Rhine). Lateron some other 

 locahties hâve been discovered : ail are situated on the 



