90 MUTATIONS, VARIATIONS, AND RELATIONSHIPS OF THE OENOTHERAS. 



(10) The inference seems justifiable that individual species become less 

 variable as they grow older, and that this decrease is compensated for by the 

 fact that when a new species springs into existence, it has a greater degree of 

 fluctuability than its parent. Such saltations are the starting-points from 

 which series with decreasing fluctuation follow. 



(n) O. parviflora, which has been known in Europe since 1759, has been 

 found in its native habitat in America in the same manner that 0. grandiflora 

 was traced to its original habitat. This leads to the hope that 0. lamarckiana 

 may be found in a wild state. 



(12) The species of evening-primrose of eastern America are distributed 

 in such manner that the most closely related species overlap in distribution. 

 This conclusion is true, no matter upon what taxonomic basis the forms 

 are classified. Similar conditions in Crataegus and Opuntia are cited. 



(13) Two bud-sports have been followed through two generations and 

 found to be constant. The sport in one case embodied the recessive char- 

 acters of a hybrid combination showing alternative inheritance, the recessive 

 qualities being thus activated and extracted in the first generation, coming 

 true thereafter. 



(14) The action of reagents having an osmotic and a chemical effect has 

 resulted in the induction of mutants in the progeny of Raimannia odorata 

 and Oenothera biennis. The mutants thus induced have been tested to the 

 second and third generation and found to come true to their newly assumed 

 characters. 



(15) The induction of mutants by the action of reagents is a conclusive 

 demonstration of the fact that hereditary characters may be altered by 

 external forces acting directly upon the reproductive mechanism. The 

 action of the reagents used experimentally is simulated by many conditions 

 occurring in nature. 



