MUTATIONS, VARIATIONS, AND RELATIONSHIPS OF THE OENOTHERAS. 77 



again but a small percentage survives to become bearing trees. As the number of trees 

 reproducing the general features of the original may be a hundred to one of the more strik- 

 ingly aberrant forms, we may see that though individual instances may be common, we are 

 never likely to meet many trees of one stamp. Once in a while an individual tree may find 

 itself in a situation favorable to the preservation of a number of seedlings, which might 

 endure until again reproductive; in such cases a marked variety may originate and make 

 its way over the earth. 



I have often thought it probable that in time a few individuals of these suddenly intro- 

 duced forms might again leap into new features, and then if they should be able to sustain 

 themselves we should have new species quite independently of any principle of natural 

 selection. 



The negative implied by the context is supplied in brackets and indicated 

 by italics. 



The above are by no means to be the earliest formulations of the hypothet- 

 ical conclusion as to the importance of sports in phylogeny. Among others 

 which might be mentioned the statement by Kerner in 1869 is worthy of 

 citation. He says: 



Die Arten die uns gegeniibertreten, sind nur Stadien and haben als solche zwar fur eine 

 gewisse Zeit Konstanz, konnen sich aber friiher oder spater in andersgeformte Arten auflo- 

 sen. Thatsache ist es, dass alle Pflanzen friiher oder spater einmal vereinzelte Abarten, 

 d. i. Sprosslinge zu erzeugen in Stande sind, welche in ihren Merkmalen von der Mutterart 

 abweichen, und zahlreichen Erscheinungen drangen uns zu der Annahme, dass unter dem 

 zusammentreffen giinstiger Bedingungen solche Abarten die Ausgangspunkte neuer Arten 

 werden. 



Among other recent observations is that of Schaffner (1906) concerning 

 a derivative of Verbena stricta which bore pinkish-white instead of the deep 

 purple flowers of the species. The aberrant form was present in many thou- 

 sands of individuals among the typical specimens, with which it seemed to be 

 in successful competition. Tests have not yet been made to determine 

 whether or not it does not readily cross with the parental form, or whether it 

 is dominant or recessive with regard to the more important differentiating 

 character. In any case, however, its mutative origin is based upon evidence 

 similar to that which zoologists seem willing to accept as proof of mutation in 

 animals, and its successful maintenance against parental competition is an 

 established fact. 



Many of the observations brought forward by various authors concern 

 species which have been long under cultivation, and so many facts reported 

 from horticultural material have been found to be unguarded against errors 

 affecting purity of lineage that much prejudice exists with respect to data 

 obtained from domesticated forms. So far as the effects of actual tillage or 

 domestication are concerned, these prejudices are without foundation, since 

 at the present time no well-founded evidence exists to show that cultural con- 

 ditions have ever produced alterations which were strictly and continuously 

 inheritable under environic conditions other than those by which the altera- 



