174 F. W. C. Areschoug. 



2. The neiv Jonas, whether species, subspecies or varieties, that have uri- 

 sen lipon fhe Scandinavian peninsula, are, at hast a large portion of them, 

 not hybrids, and Juice not been originated from such forms. 



h is not, of course, my meaning to deny the presence of hybrids, even 

 within this genus. Perhaps, one and another form of R. corylifolius has ari- 

 sen by a cross between varieties of this species (page 102 — 111). But several 

 of these varieties, as well as all the other brainbles, arising in our country, have 

 certainly neither directly nor indirectly arisen through hybridising (page b — 7). 

 For they, in general, do not take any intermediate place between other forms, 

 as is the rase with hybrids. And in addition, the brainbles in this country 

 seldom grow so mixed with each other, that a cross between them could come 

 in question. 



The above mentioned forms, whieh we presumed to have arisen on the 

 Scandinavian peninsula and which are raore or less peculiar to our flora, could 

 not have arisen by hybridising. If we turn in the first instance to R. scani- 

 cus and horridus, both of which are the most interesting brainbles, no other 

 species can be found in our country, that by a nmtual crossing could have 

 produced them. And the same holds good of R. relatus and R. polyanthe- 

 mos. Certainly, oue can imagine that the former was a hybrid of R. cordi- 

 folius and fruticosus. But against this, one can with good reason object 

 that R. relatus grows at the distance of several Swedish miles from R. cordi- 

 folius. And the varieties which grow here of R. thyrsoideus, Lindebergii, 

 villicaulis and nitidus, can not have arisen by a cross between the typical 

 species and the others. For they have no corresponding characteristics with 

 the other species living in their neighbourhood. 



3. 1/ >s partly flu 1 climatic conditions, vis, a Ion- temperature in conjunc- 

 tion with the great dampness of the air, caused by the isolated site of fhe 

 country; partly quite /neu/ conditions, particularly the greater or less dampness 

 um/ fertility of ihr soll, Hatt must have inßuenced /he Scandinavian brambles 

 und induced them In develope peculiar forms (pages 8 — 14, 19 — 114). The 

 cliniate operates upon the />ru>ulilrs in such a manner, /hat stipitate glandules 

 become scanty, the hairiness /hin, tlu armature for the mos/ part weak and 

 uniform, Ihr leaves large um/ shortly stalked und the inflorescence less ramified 

 um/ rather few-ßowered. These general changes are usually followed by others, 

 which cannoi be considered as IIa immediate effect of climate (page 9). Poor 

 soil produces strongly reduced forms, /Im/ have small, often terete turiones, most 



