78 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



.seeds all respond and produce a host of seedlings. According to Darwin 

 and Wallace, only one or two ought to be able to survive in a garden and! 

 all the rest ought to perish. Nothing of the kind occurs, for all would 

 survive and prove themselves equally fit to live if they were not pulled 

 up and thrown away. They all responded to the rich soil and vary alike 

 in all essential features, viz. a fleshy enlarged root with larger and. 

 smoother foliage than that of the parent wild plant. 



The differences we see in the shapes and colours of market forms of 

 Carrots fall under the rank of '-individual differences," and are non- 

 varietal, though the Garden Carrot, taken as embracing all cultivated 

 races, might be called a variety of the wild species ; for if it had been 

 discovered wild, and its origin unknown, it would undoubtedly have been 

 recognised as a variety of Daucus Carota, var. crassiradix. 



The point to remember is that as long as plants are growing wild,, 

 generation after generation, under constantly similar conditions their 

 variability is not called into action beyond producing minute individual 

 differences, of no account in classification. 



If, however, plants and animals migrate, as by the seeds of the former 

 being transported by birds &c, to some different type of locality, then 

 more pronounced changes may be expected to take place in nature, as they 

 do under cultivation. 



Thus Darwin observes: — " Alphonse de Candolle and others have 

 shown that plants which have very wide ranges generally present varieties ; 

 and this might have been expected, as they are exposed to diverse physical 

 conditions." * 



A.S an illustration of what might be called " exaggerated individual 

 differences " in a wild plant the Lesser Celandine [Ranunculus Ficaria) 

 may be taken. In England it varies slightly according to its locality,, 

 often producing conns in the axils of the long-stalked leaves when growing 

 in shady places ; but it has none in the open meadows. The size of the 

 blade varies a little, and the number of petals &c. 



In Malta, under a different climate, the whole plant grows to be a much 

 finer plant, the leaf -blades and flowers being usually much larger than 

 those of our English plants. Hence botanists have called it var. Calthce- 

 . as it somewhat resembles the Marsh Marigold (Caltha palustris). 

 Speaking generally, however, Darwin was undoubtedly wrong in crediting 

 '•individual differences" among wild flowers with being a usual source 

 of varieties, much less of species. 



I >r. W allace appears to disagree with Darwin on this point, as he says r 

 " In securing the development of new forms in adaptation to the new 

 environment natural selection is supreme. Hence arises the real 

 distinction, though we may not always be able to distinguish them, 

 between specific and non-specific or developmental characters. The 

 former an- those definite though slight modifications through which each 

 ik v. -i, i i. actualh became adapted to its changed environment. They are 

 therefore in their very nature useful. The latter [i.e. Darwin's individual 

 I "> r< nce> are due to the laws which determine the growth and develop- 

 ■ nt of the organism, and therefore rarely coincide exactly with the 

 limits of a species." f 



♦ Origin drc, p. 43. f Natural Science, vol. vi. p. 217. 



