10 The Significance of Horticultural Varieties. 



tendency to become fixed and so to 1)ecome races : in the 

 same way these races would later be transformed into 

 species. This is the generally accepted view. 



This view is based, as I attempted to show in the first 

 part of the first volume, on an unwarranted extension 

 of Darwin's theory of selection. Darwin argued from 

 the results obtained in horticulture; but these, at least as 

 described in the works of the best authorities, do not 

 seem to me to justify such an extension. 



According to the prevailing view, man has the power 

 to produce any desired amelioration in any species ready 

 to hand. All characters vary and all that need be done 

 would be to isolate the extreme variants and to breed 

 further from them. The process takes some time of 

 course but in many species the experiment is already 

 lasting about half a century. But the advances which 

 have been made, and which are of the very greatest prac- 

 tical importance, do not tally with this assumption. On 

 the contrary we learn from them that for much that has 

 been attained much has proved unattainable. 



The comparative studies of systematists show us that 

 almost eveiywhere there exist unperceptible transitional 

 stages between the smallest differences and perfectly dis- 

 tinct species. This forms a weighty argument for, hut 

 no proof of, the prevalent view. For we have to reckon 

 here with transgressive variability (Vol. I, Part II, § 25, 

 p. 430), which tends to blur the boundaries of related 

 groups. 



I have indicated in the foregoing section (§1) the 

 principles on which in my opinion an elucidation of the 

 process in question must be based. If a small anomaly 

 is found in a wild or cultivated species, and a new and 

 constant form is raised from this bv selection, the whole 



