138 USES OF PLANTS BY INDIANS [BTH. ANN. 33 
species used and their many uses show considerable development of 
practical plant economy, or economic botany. 
All these considerations of the relations between the aboriginal 
human population and the flora of the region are instructive to us 
as indicative of what must have been the early stages in the develop- 
ment of our own present highly differentiated botanical science. In 
this study of ethnic botany we have opportunity to observe the be- 
ginnings of a system of natural science which never came to maturity, 
being cut off in its infancy by the superposition of a more advanced 
stage of culture by an alien race upon the people who had attained 
the degree of culture we have here seen, 
