THE EVIDENCE OF EVOLUTION. 395 



their occurrence can be^predicted in some cases with euoii2;h probal)i]ity 

 to justify the trial.- Color changes in flowers, double flowers, regular 

 forms from labiate types, and others have been joroduced more or 

 less at will in my garden, and under conditions which allowed of a 

 close scientific study. The suddenness of the changes and the per- 

 fection of the display of the new characters from the very beginning 

 Avere the most striking results. 



These facts, hoA\ever, only gave an experimental proof of phenom- 

 ena which were historically known to occur in horticulture. They 

 threw light upon the way in which cultivated plants usually produce 

 new forms, but between them and the real oi-igin of species in natui-e 

 the old gap evidently remained. 



This gap, however, had to be filled out. DarwiiTs theory had con- 

 cluded with an analogy, and tliis 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 pro- 

 ducing new forms. This species has now ])een observed in its wild 

 locality during eighteen years, and it has steadily continued to repeat 

 the phenomenou. I have brought it into my garden, and here, under 

 my very eyes, the production of new species has been going on, rathei" 

 increasing in rate than diminishing. At once it rendered superfluous 

 all c(msiderations and all more or less fantastical explanations, i-eplac- 

 ing them by simple fact. Tt opened the way for further investiga- 

 tions, giving nearly certainty of a future discovery of analogous proc- 

 esses. Whethei- it is the type of the production of species in nature 

 or (mly one of a more oi- less large group of ty])es can not yet be 

 decided, but this is of no imj)ortance in the present state of the sub- 

 ject. The fact is that it has l)ecome possible to see species originate, 

 and that this origin is sudden and oljeys distinct laws. 



The species which yielch'd these important results is an American 

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

 of the most conunon and most l)eautiful among the wild flowering- 

 plants of this country. It is an evening prinn-ose, 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 primrose," 

 and produces crowns of large and l)right yellow flowers, which have 

 even secured it a place among 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 opposition 

 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 tlie agency of the environmental forces. All 

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



