DE VRIES'S EVIDENCE 



XXI 



has been studied at La Garde St. Cast, on the coast 

 of Brittany, in 1899, 1904, and 1907 by G. A. Boulenger, 

 F.R.S., and also by Mr. Charles Bailey at St. Anne's-on- 

 the-Sea, North Lancashire, and neither of these naturalists 

 finds the same phenomenon exhibited, although the 

 latter observer appears to have discovered about two of 

 De Vries's ' species '. Boulenger's conclusions are quoted 

 in full in the following paragraph : — 



'To sum up, I would suggest the possibility of the 

 Mutations-theorie being based on false premisses. 

 De Vries has assumed, without any justification, that 

 Oenothera Lamarckiana is a natural species. The fact 

 that it was originally described from a garden flower, 

 grown in the Paris Jardin des Plantes, and that, in spite 

 of diligent search, it has not been discovered wild any- 

 where in America, favours the probability that it was 

 produced by crossing various forms of the polymorphic 

 CE. biennis, which had previously been introduced in 

 Europe. If it be so, and the onus probandi of the 

 contrary rests with the mutationists, we have no evidence 

 of mutations in the phenomenon observed by De Vries, 

 but simply one of those cases of Mendelian disjunction of 

 hybrids to which he was the first to call the attention 

 of the naturalists of the present generation. The 

 characters of several parent forms, which may, for all we 

 know, have originated through fluctuating variation, have 

 remained latent in some individuals of CE. Lamarckiana 

 and reappear in different combinations, thus producing 

 the appearance of distinct " species," each definable by 

 several characters, springing up under our eyes.' x 



In the recent work of Macdougal, Vail and Shull we 

 are told that 'fixed hybrids constituting species were 

 secured in combinations of O. lamarckiana and O. cru- 

 1 Journal of Botany, October, 1907. 



