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simple forms like the primrose are easily and quickly 

 mutated by the dropping out of a character, but that 

 this is not the way that changes occur in the animal 

 kingdom. He makes the distinction between "fluctua- 

 tions," which constitute one type, and always occur- 

 ring, but are not of value in forming new species, and 

 "mutations," which happen to occur from time to 

 time. 



Mutations do not necessarily produce greater changes 

 than fluctuations, but such as may become, or rather are, 

 from their very nature, constant. He says: "Some 

 authors have tried to show that the theory of mutation is 

 opposed to Darwin's views. But this is erroneous. On 

 the contrary it is in the fullest harmony with the great 

 principle laid down by Darwin." 



He says that in natural selection, environment usually 

 plays the larger part. 



"Even if saltatory variations do occur we cannot 

 assume that these have led to forms which are capable 

 of survival, under the conditions of wild life. " * * * 

 (August Weissman). He remarks, in the same connec- 

 tion, that the experiments of De Vries with the evening 

 primrose, were made with the artificial, not the wild 

 plant. It was first discovered in the Jardin des Plantes. 

 in Paris, and does not appear to exist anywhere in 

 America, as a wild species. 



Alfred M. Girard says : "A great number of biologists 

 have believed that they found in the splendid studies of 

 De Vries, unanswerable arguments against the theory of 

 selection. It is impossible for me to share their opinion. 

 I should say, even in examining the question closely, and 

 in penetrating to the bottom of the matter, it is im- 

 possible for me to find in the theory of mutations, any- 

 thing except a useful complement of the Lamarkian and 

 Darwinian doctrine of continuous variation. ' ' 



