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 



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