THE THEORY OF MUTATIONS 103 



De Vries has, moreover, made his own observ- 

 ations on a plant in the neighbourhood of Amster- 

 dam which is, or was recently, in the condition 

 of sending off new lateral species. This plant is 

 the well-known large-flowered evening primrose 

 (Enothera Lamarckiana, which is supposed to have 

 come from America, though this point is doubtful, 

 and to have been introduced into the gardens of 

 the Musee d'Histoire Naturelle, at Paris, by no 

 less a person than Lamarck himself, after whom 

 it is named. It is one of those plants which freely 

 " escapes," to use the botanical phrase, and is 

 often to be found, therefore, in a wild condition. 

 It was in such a state, at Hilversum, near Amster- 

 dam, that de Vries came across a number of these 

 plants. But the remarkable thing was that in 

 addition to the well-known and unmistakable (E. 

 Lamarckiana there were a number of other var- 

 ieties or species growing with it. These species 

 are not only new but appear to be perfectly con- 

 stant, so that here again we seem to be able to 

 record the birth into the world for the first time 

 of a new species. For the exact description of 

 these new species the botanical inquirer must be 

 referred to the pages of de Vries' work. There too 

 he will find an account of the experiments of that 

 botanical observer on a peculiar variety of species 

 of toadflax, the peloric variety. 



From these and other observations described 

 at great length in his book he deduces the con- 

 clusions that new elementary species appear sud- 

 denly and without any intermediate steps leading 

 up to them ; that the new forms spring laterally, 



