1340 ANALYSIS OF THE FOUR PRINCIPLES (CONTINUED). 
What is usually called the amalgamation of races is regressive tsola- 
tion. Itis a form of racial demarcation, in which the boundaries are 
so changed that two or more slightly divergent varieties or races are 
interfused and become one. But, as I have already suggested, the 
limits within which regression of this kind can take place are compar- 
atively small. 
Regressive partition takes place when divergent forms of civiliza- 
tion become commingled and blended. In the case of human races 
it often introduces regressive isolation. 
The most familiar of these four regressions is regressive isolation, 
that is, racial amalgamation, to which Darwin’s work on cross and self 
fertilization has called attention. The chief significance of the prin- 
ciple lies in its producing a certain limited undoing of isolation and in 
its giving plasticity and variability to the compounded stock. Amal- 
gamation usually arises through the entrance of divergent races into 
the same region before their sexual and social instincts or the physio- 
logical and structural coadaptations of the sexes have become so 
divergent as to prevent interfusion. Under such conditions what- 
ever determines the bringing together of the races in the same region 
determines the nature of the amalgamation. When human races are 
brought together in the same region, the rapidity of amalgamation is 
determined largely by racial instincts and social conditions. 
1. Reversal of Partition and Isolation in Man. 
The most remarkable feature in the evolution of civilized man ts the 
reversal of the processes of partition and of tsolation and the breaking 
down of the social and racial segregations that have been progressing 
for countless generations. The leading factors in this process of 
coalition are social rather than racial; but the final result will un- 
doubtedly be a great reduction of the number of races, and possibly a 
blending of all in one generalized type, resulting from the amalgama- 
tion of all the racesin one. It is, however, possible that the barriers 
preventing marriage between certain races of men will become more 
fixed than ever, even though the intercourse of industrial, commercial, 
and national life becomes increasingly intimate. The era of commer- 
cial intercourse has been inaugurated and will never be reversed. 
Again, the smaller nations are being absorbed into the larger nations; 
but what the final result will be on the multitude of races and castes 
can not be easily foretold. 
