372 THE EVIDENCE OF EVOLUTION. 



This gap, however, had to be filled out. Darwin's theory had 

 concluded with an analogy, and this analogy had to be replaced by 

 direct observation. 



Success has attended my efforts even on this point. It has brought 

 into my hands a species which has been taken in the very act of 

 producing new forms. This species has now been observed in its 

 wild locality during eighteen years, and it has steadily continued 

 to repeat the phenomenon. I have brought it into my garden, and 

 here, under my very eyes, the production of new species has been 

 going on, rather increasing in rate than diminishing. At once it 

 rendered superfluous all considerations and all more or less fan- 

 tastical explanations, replacing them by simple fact. It opened 

 the way for further investigations, giving nearly certainty of a 

 future discovery of analogous processes. Whether it is the type 

 of the production of species in nature or only one of a more or less 

 large group of types can not yet be decided, but this is of no impor- 

 tance in the present state of the subject. The fact is that it has 

 become possible to see species originate, and that this origin is sudden 

 and obeys distinct laws. 



The species which yielded these important results is an American 

 plant. It is a native of the United States, and nearly allied to some 

 of the most common and most beautiful among the wild flowering 

 plants of this country. It is an evening primrose, and by a strange 

 but fortunate coincidence bears the name of the great French founder 

 of the theory of evolution. It is called 'Lamarck's evening prim- 

 rose,' and produces crowms of large and bright yellow flowers, which 

 have even secured it a place amongst our beloved garden plants. 



The most interesting result which the observation and culture 

 of this plant, have brought to light is a fact which is in direct oppo- 

 sition to the current belief. Ordinarily it is assumed that new species 

 arise by a series of changes in which all the individuals of a locality 

 are equally concerned. The whole group is supposed to be modified 

 in a distinct direction by the agency of the environmental forces. 

 All individuals from time to time intercross, and are thereby assumed 

 to keep equal pace in the line of modification, no single one being 

 allowed to go distinctly ahead of the others. The whole family 

 gradually changes, and the consequence would be that the old form 

 disappears in the same degree as the new makes its appearance. 



This easy and plausible conception, however, is plainly contra- 

 dicted by the new facts. There is neither a gradual modification nor 

 a common change of all the individuals. On the contrary, the main 



