APPENDIX II. 



INTENSIVE SEGREGATION, OR DIVERGENCE THROUGH 

 INDEPENDENT TRANSFORMATION.* 



I. Classipication of the Forms op Intensive Segregation. 



In a previous paper on divergent evolution I have enumerated many 

 classes of natural causes which produce either separate or segregate 

 generation,! and which, in their combined action, tend to produce 

 cumulative segregation and divergent evolution in every part of the 

 organic world. I have there shown, with sufficient fulness, that cumu- 

 lative segregation always produces cumulative divergence or poly- 

 typic evolution ; but I have not fully shown how separation from the 

 first involves more or less segregation, or how segregation, which at 

 first divides the species into sections with reference to some one en- 

 dowment, is always tending toward intensified segregation in which 

 the sections present differences in regard to an increasing number of 

 endowments. 



After expounding the principles on which these laws of divergence 

 rest, I will give a few examples of divergence, calling attention to the 

 complete correspondence between the facts of nature and the prin- 

 ciples expounded in this and the previous paper. 



* From the Linnean Society's Journal, Zoology, vol. xxiii. Read December 

 19, 1889. 



t Separate generation, or separation, is the indiscriminate division of a species 

 into sections that do not intergenerate. Segregate generation or segregation is 

 the independent generation of different sections of a species when the sections are 

 composed of somewhat divergent classes of variations. Isolation differs from 

 selection in that the latter denotes the exclusion of certain kinds from opportunity 

 to propagate, while the former denotes the division of those that propagate into 

 classes that are prevented from intergenerating. Isolation, or the prevention 

 of intergenerfl.tion, whether it be through separation or segregation, I also call 

 independent generation. Darwin used isolation as equivalent to geographical 

 separation, while later writers have come to use it as equivalent to independent 

 generation. 



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