1 72 F. W. C. Areschoug. 



above all with R. corylifolius. But the forms that arose from this species, 

 caii hardly deserve to be raised to the rank of species. Seveial of the Scan- 

 dinavian corylifolians (page 112) liave immigrated from the Danish Islands, or 

 the continent of Europé, and here hold themselves rather like the correspon- 

 ding continental forms. Others have been developed here from these forms and 

 seein to be endende. R. corylifolius (page 13), as well as R. suberectus, has 

 the largest geographical area of all the black-fruited brambles and surpasses 

 them, in refeience to their abundance on the Scandinavian peninsnla. Also R. 

 in sula ris whose immigration dates from a much låter period than that of R. 

 corylifolius, has here prodnced a new species, R. polyanthemos, as well as 

 several varieties. It is eonfined to the west eoast of Sweden and the south of 

 Norway. The forms which this species produced in Bohuslän and Norway, 

 are there isolated from the typical species. One must therefore think, that R. 

 insularis, in the just named träets, could not hold itself unchanged. It is the 

 same case with R. scanicus which is eonfined to the most southern part of 

 Sweden, and therefore must have immigrated låter. This species has probably 

 (page 134) arisen from R. Arrhenii which is not to be found in Sweden. R. 

 glandulosus shows little inclination to vary, in our country, but still it has 

 produced a new species, R. pallidus. R. pallidus is also very constant, but 

 has, however, given rise to R. horridus. R. fruticosus (R. plicatus, Whe.) is 

 one of the blackfruited brambles that has the widest geographical extension on 

 the Scandinavian peninsula (page 18), and is exceeded, as regards abundance, 

 only by R. corylifolius. Though that species is somewhat changeable (page 

 lli:l), it has not produced any remarkable varieties here. and only one spe- 

 cies, viz, R. relatus. This species has arisen upou only one spöt, in the east 

 eoast of Sweden. 



R. thyrsoideus (page 148), Lindebergii (page 144), villicaulis (page 

 151) and nitidus (page 162) possess small power to vary, but still have pro- 

 duced isolated varieties. The two first named species are spread över a rather 

 large geographical area, but the two last appear within a smaller one. 



The circumstance, that the brambles which occur in our country, grow in 

 the neighbourhood of the supposed parent species, seems to me to give a strong 

 support to niy supposition, that they derive their origin from these very species. 

 Thus, Ii glandulosus, pallidus and horridus (page 127) grow within the 

 same small district un the easl eoast of Sweden, but none of them arise out- 

 side it any where on the Scandinavian peninsula. R. polyanthemos (page 



