T42 THE THEORY OF MUTATION 



and groundwork of the views which he puts for- 

 ward. 



The plant which afforded the material for this dis- 

 covery is known as (Enothera Lamarckiana that is to 

 say, this is the name of the old species from which the 

 new species were found to be arising. 0. Lamarckiana 

 is an American plant, but the specimens which de Vries 

 found to be in a state of mutation had made their 

 escape from a garden, and were running wild over a 

 disused potato-field near a town called Hilversum, in 

 Holland. On examining these plants, de Vries found 

 two distinct new forms, which were quite unlike the 

 remainder. Each kind occurred in an isolated patch, 

 as if it had arisen from the seed of a single plant. 



No description of either of these forms was to be 

 found in botanical literature, nor were there specimens 

 of them in any of the great herbaria. But when de 

 Vries took seeds from some of the plants and sowed 

 them in his garden, he found that the new forms came 

 true to type the plants produced resembled the 

 parents from which the seeds were taken, and not the 

 normal form of 0. Lamarckiana. 



Here, then, we have a case in which two new species 

 had originated from an old one in a state of nature. 

 But de Vries went further than this, and took measures 

 for observing the actual origin of new forms in the 

 cultivated offspring of the semi-wild (Enothera. 



For this purpose he transplanted a number of roots 

 from the field where they were growing, and also took 

 seed from a number of other plants, and from these he 

 cultivated large numbers of seedlings for a series of 



