Distinction Bctzvecn Species and I 'arictics. 579 



is a fundamental antithesis between ancient and reeeni 

 characters, which hnds its expression both in the ])lic- 

 noniena of specific differentiation, and in those of arti- 

 ficial hybridization; for on the one hand forms can arise 

 from others without the production of new factors, simjjl)- 

 by the transference of factors already present into another 

 condition, as from latent to active ; and on the other hand, 

 by the genuine appearance of new elementary characters. 

 Progress in organization is due to the latter process, 

 whilst the former is to a large extent the cause of the di- 

 versity of organic life. 



If we compare this experimental result with the abu\e 

 theoretical considerations, we mav assume that the 'lis- 

 tinction between older and younger characters consists 

 in the difference between the formation of a new factor 

 and the transposition of factors already present. On 

 the basis of the doctrine of creation the origin of new 

 units must be explained as being due to a supernatural 

 cause, but no one has as yet applied this theory to the 

 change in position of factors already present. Moreover 

 in the light of the idea of evolution also the antithesis 

 mentioned has its real and full significance. 



It would lead me too far to analyze here the concep- 

 tions of other authors on these points, but such an anal- 

 ysis has led me to the conviction that the difference be- 

 tween the formation and the transposition of factors cor- 

 responds closely to the difference which the best systeni- 

 atists consider to exist between species and varieties.^ 

 A form which owes its origin to the producti(^n of a new 

 internal factor is to be regarded as a si-)ecies : a lornj 

 which owes its peculiarity merely to the change in con- 

 dition of a factor already present is to be regarded as a 



* See also Vol. T, p. 185. and Vol. IT. pp. Ji-/^- 



