142 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 nothera Lamarckiana—that is to 
say, this is the name of the old species from which the 
new species were found to be arising.| O. 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 O. 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 Gnothera. 
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 
