Some Observations 011 the Genus Kubus. 179 



each other, fchat it seems to me very likely, that in England they arose from 

 a single species. 



7. The i" w varieties or species, that arose from certain immigrant forms, 

 hare not </er/l/>pcd yradnnlly, hut hare ar/sen suddenly and, so to say, at once 

 (page 29). The forms immigrated hither could not, at once on their arri- 

 val, have changed into new Jonas. They hare certainly //red here for a lon- 

 gt r time unchanged. Bat in Urne the outward circumstances have by degrees 

 /and/ar,/ new tendencies in the plant, am/ whén fliese have acquired sufficient 

 energy to throw off the inherited disposition, they at once appear in the outward 

 structure of the plant. 



I have been led to this opinion regarding the origin of new forms, by 

 paying attention to the different circumstances of the species or varieties pecu- 

 liar to the Scandinavian flora. In very many, indeed in nrnst cases, no iriter- 

 mediate forms are to be found between the new forms and the species that 

 have prodüced them. And as it is very probable, that these very species have 

 immigrated comparatively late to the country, it is hardly probable, that inter- 

 mediate forms, if such were to be found, could have had time to disappear. 

 This is so much the less to be imagined, as intermediate forms are still to be 

 found. arising from R. corylifolius and certain species belonging to the group 

 Suberecti, thougli they are of greater age in our country than niost of the 

 other species. In confir mation of this, allow me to cite, R. glandulosus, 

 pallidus and horridus (pages 12:1, 124), R. scanicus and Arrhenii (page 

 131), Ii. fruticosus and relatus (page 158), R. thyrsoideus and its variety, 

 subvelutinus (page 153), R. nitidus and its variety grandifolius (page 1(!2). 



8. Intermediate forms indicate tio yrades in a successive evolution of 

 one form to another, hut are, so to say. parallel forms (pages 6'.9, 104—111) 

 which have arisen independently of each other, under the influence of outward 

 conditions, that more or less recede from those l/y which fh> : typical form 

 arose. 



In the introduction (page 2'.l), I have expressed the opinion, that new foiins 

 can arise either at once, or gradually and with the production of intermediate 

 forms. I imagined, that the intermediate forms constituted the phases of evo- 

 lution, that a form had to undergo, when it was to produce a new species. I 

 -u|>posed also, that when intermediate forms are found between two forms, it 

 could be assumed, that the one form had developed from the other, and that this had 

 happened within the boundaries of the country. To be sure, it seeméd to me 



