DISTINCTION BETWEEN SPECIES AND VARIETIES. 315 



nal influences will account. Thus the seeds of the same indi- 

 vidual of the beautiful Fuchsia, now naturalised in our green- 

 houses and in the open air of the milder parts of Britain, have 

 been known to produce plants, whose flowers differ so much in 

 shape and in the proportional length of the calyx and corolla, 

 that, if these had been collected and compared without the know- 

 ledge that they had been produced from one plant, they would 

 have been regarded as distinct species, perhaps even (so striking 

 is the difference) as distinct genera. Nearly the same is the 

 case with another South American Plant now much cultivated 

 in Britain, the Calceolaria or slipper-shaped flower ; of which 

 an immense number of varieties, differing widely in the shape as 

 well as the colour of the flower, are now known, almost every 

 Horticultural Exhibition having a new one : and the beautiful 

 South American Amaryllis has a like tendency, of which the 

 gardener has taken similar advantage. 



476. Hence in discriminating what are real species from what 

 are simply varieties, the Botanist is treading on very insecure 

 ground, until he has ascertained, for every species, its tendency to 

 run into varieties of form, whether spontaneous, or induced by 

 change of external conditions. His greatest difficulty arises from 

 those cases, in which have arisen what are termed permanent 

 varieties, which reproduce themselves with the same regularity as 

 do real species. An instance of this in the Animal Kingdom is 

 that of the different races of men, which are respectively distin- 

 guished by marked peculiarities, that are regularly repeated 

 through each generation ; so that many naturalists have been 

 inclined to regard them as really distinct species. There is, 

 however, good evidence (independently of the Mosaic History) 

 to prove that they have all descended from a common stock. 

 Precisely the same is the case in regard to Plants ; many races 

 of which, even in Britain, are still under discussion amongst 

 Botanists ; some maintaining that they are distinct species, and 

 others that they are but varieties. Thus of the Willow, 71 

 species have been stated by one authority to exist in Britain, 

 whilst another reduces them to 29. The genus Rubus or com- 

 mon Bramble has been thought to contain 21 British species, 



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