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REV. J. T. GTJLICK ON DIVERGENT EVOLUTION 
Preliminary Definitions. 
Believing that great obscurity has often been introduced into 
the discussion of biological subjects by the use of terms of un- 
certain import, I have endeavoured to obtain greater precision by 
giving definitions of the terms I have introduced ; and for the 
sake of indicating what words are thus used with special and 
definite meanings, they have been distinguished by capitals. A 
few of these definitions are here given, and others will be given in 
the body of the paper. 
An Inter gener ant, or Inter generating Group , is a group of 
individuals so situated and so endowed that they freely cross 
with each other. 
Regeneration , or Independent Generation. In harmony with the 
fundamental doctrines of evolution, I assume that each species 
was at one time a single intergenerant ; but we find that many 
species are now divided into two or more intergenerants, between 
which there is little or no intercrossing. This state of freedom 
from crossing I call Segeneration. Segeneration is of two kinds, 
Separate Generation and Segregate Generation. 
Separate Generation , or Separation, is the indiscriminate 
division of a species into groups that are prevented from freely 
crossing with each other. 
Segregate Generation, or Segregation, is the intergeneration 
of similar forms and the prevention of intergeneration between 
dissimilar forms. 
Select Generation , or Selection, is the partial or complete 
exclusion of certain forms from the opportunity to propagate, 
while others succeed in propagating. The generation of any 
form is select with reference to the non-generation of forms that 
fail of propagating, and segregate with reference to the genera- 
tion of forms that propagate successfully, but separately. 
Adaptational Selection is exclusive generation that depends 
upon superior adaptation either to the environment or to other 
members of the same species. 
Natural Selection is the exclusive generation of those better 
fitted to the natural environment, resulting from the failure to 
generate of those less fitted. 
Artificial Selection is the exclusive generation of those better 
fitted to the rational environment. 
Befiexive Selection is the exclusive generation of those better 
