58 USES OF PLANTS BY INDIANS [ETH. ANN. 33 
currents of air. And the winds themselves were the paths of the 
Higher Powers, so they were constantly reminded of the mystic 
character of this tree. 
The Sacred Pole, an object of the greatest veneration to the 
Omaha Nation, was made of cottonwood. 
These three trees will serve as examples of plants to which mys- 
tery is ascribed and which had symbolism in the rituals of religion. 
In the chapter on the aboriginal uses of plants, where the plants are 
listed according to taxonomic order, several others will be found. 
Tt will be found that the sense of beauty and the pleasure-giving 
arts will, with every people, find outlet and expression by means of 
the natural products of their own region. Much of the enjoyment 
of art arises from association. The tribes of Nebraska found within 
their range many plants yielding pigments to gratify the love of 
color; they also found many plants whose leaves or seeds yield 
fragrance. All of these scents are clean and wholesome and redolent 
of the pure outdoors and freshness of breezes from nature’s garden 
and the farthest removed from any suggestion of hothouse culture 
and of the moiling of crowds. By a whiff of any of these odors one 
is mentally carried, by the power of association and suggestion, to 
the wide, quiet spaces, where the mind may recover from throng- 
sickness and distraction of the multitude and regain power and 
poise. 
Native plants of the region also furnished the materials for per- 
sonal adornment, although it is noteworthy that it has not been found 
that flowers were used for this purpose by any of the tribes of the 
plains. It was often remarked that the people admired the wild 
flowers in their natural state, but they never plucked them. How- 
ever, beads and pendants were made from many seeds. 
INFLUENCE OF HUMAN POPULATION ON FLORA 
It would be most interesting if we could determine with any degree 
of accuracy the efficient factors in the redistribution of vegetation 
over the ice-devastated region after the glacial retreat. We should 
like to know the distance, velocity, and direction, and the active 
agents, eolian, hydrographic, faunal, and anthropic, of the various 
currents in the resurgence of floral life over the region formerly ice 
covered. 
We see the results of human agency as a factor in plant migration 
very clearly in the introduction into this State of a number of plants 
since the advent of Europeans. Some species introduced here are 
indigenous on the Atlantic seaboard, some have been brought from 
Europe and naturalized in the Eastern States, and thence brought 
