802 Fluctuations 



proved races do not generally last very long 

 in practice; sooner or later they are surpassed 

 by new selections. Exactly so we may imagine 

 the agency of natural intra-specific selection. 

 It produces the local races, the marks of which 

 disappear as soon as the special external con- 

 ditions cease to act. It is responsible only for 

 the smallest lateral branches of the pedigree, 

 but has nothing in common with the evolution 

 on the main stems. It is of very subordinate 

 importance. 



These assertions of course, are directly op- 

 posed to the current run of scientific belief, but 

 they are supported by facts. A considerable 

 part of the evidence has already been dealt 

 with and for our closing discussion only an ex- 

 act comparison remains to be made between the 

 two detailed types of intra-specific selection. In 

 coming to this I will first dwell upon some in- 

 termediate types and conclude with a critical 

 discussion of the features of artificial selection, 

 which to my mind prove the invalidity of the 

 conclusions drawn from it in behalf of an ex- 

 planation of the processes of nature. 



Natural selection occurs not onlv in the wild 

 state, but is also active in cultivated fields. 

 Here it regulates the struggle of the selected 

 varieties and improved races with the older 

 types, and even with the wild species. In a pre- 



