224 REV. J. T. gulicjk: on divergent evolution 
that succeed in germinating in contrasted situations, the difference 
is directly due to a Diversity in the forms of Natural Selection 
affecting the seed, and the Separation is what I hereafter describe 
as Local Separation passing into Local Segregation. We there- 
fore see that what I here call Industrial Segregation depends on 
psychological powers acting in aid of divergent physiological 
adaptations to the environment, or in aid of adaptations that are 
put to different uses. 
Observation shows that there is a multitude of cases in which 
Endeavour according to Endowment brings together those simi- 
larly endowed and causes them to breed together ; and when the 
species is thus divided into two or more groups somewhat differ- 
ently endowed, there will certainly he an increased divergence in 
the offspring of the parents thus Segregated ; and so on in each 
successive generation, as long as the individuals find their places 
according to their endowments, and thus propagate with those 
similarly endowed, there will be accumulated divergence in the 
next generation. Indeed it is evident that Endeavour according 
to Endowment may produce under one environment what Natural 
Selection produces when aided by local separation in different 
environments. As it produces the separate breeding of a diver- 
gent form without involving the destruction of contrasted forms, 
it is often the direct cause of divergent transformations ; while 
Natural Selection, which results in the separate breeding of the 
fitted through the failure of the unfitted, can never be the cause 
of divergence, unless there are concurrent causes that produce 
both divergent forms of Natural Selection, and the separate 
breeding of the different kinds of variations thus selected. 
Suetudinal Intension . — Another law is usually believed to be 
connected with Endeavour which, if it exists, must conspire to 
enhance its tendency to produce divergent evolution. I refer 
to the influence which the habitual endeavour of the parents has 
on the inherited powers of the offspring. We may call it the 
law of Endowment of Offspring according to the Exercise or 
Endeavour of Parents, or more briefly Suetudinal Intension. 
The inherited effects of use and disuse have been fully recognized 
by Darwin, Spencer, Cope, Murphy, and others, and need not 
here be discussed. The one point to which I wish to call atten- 
tion is, that in order that diversity of use should produce diver- 
gent evolution, it is necessary that free crossing should be pre- 
vented between the different sections of the species in which the 
