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REV. J. T. GULICK ON DIVERGENT EVOLUTION 
fundamental distinction is between segregation produced by the 
purpose of man, which I call 
Rational Segregation, in its two forms : 
Artificial Segregation, 
Institutional Segregation, 
and that produced by nature outside of man, which I call 
Responsive Segregation ; 
while any of these forms of Segregation may be intensified by 
Independent transformation through the principles of Diversity 
of Selection, Diversity of Use, or Diversity of Direct Effects of 
the Environment ; and the combined action of Segregation with 
these and other principles of transformation I call 
Intensive Segregation. 
In the other classification, the fundamental distinction is be- 
tween segregation arising from the relations in which the organism 
stands to the environment, which I call 
j Environed Segregation , 
and segregation arising from the relations in which the members 
of the same species stand to each other, which I call 
Iiejlexive Segregation ; 
while any form of segregation belonging to either of these classes 
may be enhanced by one or more of the forms of Intension, and 
thus present what I call 
Intensive Segregation. 
The Effects of Segregation. 
The effects of Segregation can be studied to advantage in the 
vast experience that has been accumulated in the domestication 
of plants and animals. 
Artificial Segregation is caused by the relations in which the 
organism stands to the rational environment, that is to the 
purposes of man. In other words, Artificial Segregation is the 
rational form of Environal Segregation. Though the bearing of 
Segregation on the evolution of species in a state of nature has 
been for the most part overlooked, its effects have been quite 
familiar to the breeder of domestic races. 
