INTENSIVE SEGREGATION. 359 



ments; and the same cause will often produce diversity in the forms 

 of natural selection affecting the segregated sections. Cumulative 

 divergence in the methods of using the environment in the 

 different branches of the species depends upon their segregation, 

 and, therefore, increasing divergence in the forms of natural 

 selection affecting the different branches depends on their 

 segregation. But Industi'ial Segregation is not the only form of 

 In-dependent Generation that opens the way for increasing 

 diversity of natural selection. Greographical Segregation under 

 the same environment, though it does not of itself produce 

 divergent forms of selection, opens the way for change in the 

 habits of feeding with diversity of natural selection in the 

 different sections of the species. Take, for example, tlie species 

 of AcJiatinella : in Manoa and Mikiki they chiefly occupy the 

 Kukui {Aleurites triloba) and other trees, while in Kawailoa and 

 that region they neglect the larger trees and take to the Lobelia 

 and other shrubs and herbaceous plants. 



But why should the degree of divergence increase with the 

 continuance of the Segregation? The answer seems to be that 

 the combined effects of the different principles of transformation 

 in the segregated groups increase with the time of segregation ; 

 and, as independent transformation is never parallel, the diver- 

 gence increases in the same ratio. Diversity of natural 

 sekction is undoubtedly one of the principles producing this 

 divergen'-e, even when the vegetation and physical conditions of 

 the different districts are the same, for when the habits of 

 feeding change, the natural selection must usually change. But 

 there are cases of divergence accompanying Segregation in which 

 the habits of feeding seem to have remained unchanged; and in 

 such cases I explain the divergence in part by the principle that 

 separation always involves more or less segregation, and in part 

 by the influence of the four principles which I have called 

 Assimilational, Elimiuational, Amalgamatioual, and Fecundal 

 Transformation. Of these, Eliminational and Amalgamatioual 

 Transformation are perhaps the most constantly operative. The 

 principle of unbalanced Elimination is closely allied to the 

 principle that separation involves Segregation ; for both repre- 

 sent phases of the fact that any small fragment of a species is 

 incapable of propagating all the qualities of the species in the 

 exact proportion presented by the average of the species, 



LINN. JOUEN. ZOOLOGY, VOL. XXIII. 24 



