THROUGH CUMULATIVE SEGREGATION. 
199 
genera not otherwise segregated would not have stood in the 
way of their becoming different families, and that therefore 
mutual sterility has had nothing to do with their continued 
divergence ; still he seems to have failed to perceive the im- 
portant influence this principle must have had on the divergent 
evolution of the higher groups of organisms. 
The correspondences in the two papers are notwithstanding 
more remarkable than the differences. Of these, the most conspi- 
cuous is the use of the word Segregation to express the principle 
under consideration.* As I have already pointed out, I used this 
word for the same purpose in an article in the ‘ Chrysanthemum,’ 
published in January 1883 ; and again in the c Chinese Recorder r 
for July 1885, where I spoke of the “ Law of Segregation rising 
out of the very nature of organic activities, bringing together those 
similarly endowed,” and causing •“ the division of the survivors 
of one stock, occupying one country, into forms differing more 
and more widely from each other.” 
I trust that my discussion of the various forms of Segregation, 
both Negative and Positive, though presented in so condensed a 
form, will throw light on the subject of the mutual sterility of 
species ; and that in other ways my presentation of the subject 
will contribute something, not only to the theory of Physio- 
logical Segregation, but to other branches of the general theory 
of evolution. 
I should here acknowledge (what will, I think, be manifest on 
every page of my paper) that my obligations to Darwin and 
Wallace are far greater than are indicated by quotations and 
references. 
I very much regret that I have failed of obtaining a copy of 
‘Evolution without Natural Selection,’ by Charles Dixon; but, 
from his letter in ‘ Nature,’ vol. xxxiii. p. 100, 1 see that he main- 
tains “ That isolation can preserve a nou-beneficial variation as 
effectually as natural selection can preserve a beneficial variation.” 
He does not there refer to the fact, which I emphasize, that all 
divergence of a permanent character, whether beneficial or non- 
beneficial, is dependent on Segeneration either Separative or 
Segregative. 
* See paper on “Physiological Selection,” Linn. Soc. Journ., Zoology, 
vol. xix. pp, 354, 356, 391, 395, 
