Mutating Plants 
and last method of getting still more new species 
from the original strain was the repetition of the 
sowing process, by saving and sowing the seed 
which ripened on the introduced plants. These 
various methods have led to the discovery of 
over a dozen new types, never previously ob- 
served or described.” Some of these De Vries 
regards as varieties, in the sense in which he 
uses the words; others, he maintains, are real 
progressive species, some of which are strong 
and healthy, others weaker and apparently not 
destined to be successful. All these types proved 
absolutely constant from seed. ‘‘ Hundreds of 
thousands of seedlings may have arisen, but they 
always come true and never revert to the original 
O. lamarckiana type. But some of them, how- 
ever, are, like their parent form, liable to muta- 
tions.” The case of the evening primrose is by 
no means an isolated one. De Vries cites several 
other instances of plants in a mutating state. 
“The common poppy,” he says (p. 189), ‘‘ varies 
in height, in colour of foliage and flowers; the 
last are often double or laciniated. It may have 
white or bluish seeds, the capsules may open 
themselves or remain closed, and so on. But 
every single variety is absolutely constant, and 
never runs into another when the flowers are 
artificially pollinated and the visits of insects 
excluded.” Similarly the garden carnation some- 
times gives rise to the wheat-ear form. ‘‘In this 
85 
