THEOFGH CUMULATIVE SEGREGATIOlir. 



201 



fitted to the relations in which the members of the same species 

 stand to each other. Sexual, Social, and Institutional Selection 

 are forms of Eeflexive Selection. 



The Environment is nature lying outside of the Intergenerant. 

 The influence of the Environment is the sum of the influences 

 that fall upon the members of an Intergenerant, exclusive of 

 their influence upon each other. The environment of an inter- 

 generant includes members of the same species, only vi^hen these 

 members are so near that they exert an influence through com- 

 petition or otherwise, while at the same time they are so far dif- 

 ferentiated that they do not intercross ; in other words, the 

 members of the same species can mutually belong to the environ- 

 ment, only when they have acquired some of the characteristics 

 of independent species. The same environment extends as far as 

 the activities that afl'ect or may aff"ect the species extend without 

 undergoing change. 



Change in the Environment is change in the external activities 

 aflfecting the species. 



Entering a new Environment is change in the territorial dis- 

 tribution of the species, bringing either all or a portion of its 

 members within the reach of new influences. This may also be 

 called Change of Environment . 



Change in the Organism, whether producing new adaptations to 

 the environment or not, should be carefully distinguished from 

 both of the above described changes. 



Change of delations to the Environment may be produced by 

 Change in the Environment, or by Entering a new Environment, 

 or by Change in the Organism. 



As great confusion has been occasioned by the terms " Con- 

 ditions of Life" and "External conditions" being used, some- 

 times for activities outside of the species under consideration, 

 and sometimes for those within the species (as for example the 

 influence upon the seed produced by its position in the capsule), 

 I have tried to avoid their use. 



Monotypic Evolution is any transformation of a species that 

 does not destroy its unity of type. 



Polytypic Evolution or Divergent Evolution is any transforma- 

 tion of a species in which different types appear in different 

 sections. 



