THE PHANTOMS BEHIND US 
stances the results are rapid. Thus sheep lose their 
wool in tropical climates and a northern fur-bear- 
ing animal its fur. The well-being of the animal de- 
mands this change, and demands it quickly. Fish 
lose their sense of sight in underground streams; 
this loss is not so vital and it comes about much 
more slowly. A tropical climate sets its stamp upon 
the complexion and character of man, but this 
again is a slow process, as the same stress of neces- 
sity does not exist. 
In the tendency to variation — in form, size, dis- 
position, power, fertility — man differs from all 
other animals. In the same race, in the same fam- 
ily, we find infinitely varied types. Among the wild 
creatures all the individuals of a species are prac- 
tically alike. We can hardly tell one fox, or one 
marmot, or one chipmunk, or one crow, or one 
hawk, or one black duck from another of the same 
species. Of course there are slight individual differ- 
ences, but they are hardly distinguishable. Among 
the insects, one bee, one beetle, one ant, one butter- 
fly seems the exact copy of every other individual 
of its kind. The law of variation seems practically 
annulled in the insect world. 
It is the wide and free range of this law in the 
human species that has undoubtedly led to the 
great progress of the race. There has been no dead 
level — no democracy of talent — no equality of 
gifts, but only equality of opportunity. Men differ 
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