6 DOMESTICATED ANIMALS AND PLANTS 
cultivated forests, or from alcohol produced by the starchy 
grains and vegetables. 
In early days the fat of animals or of plants served for illumi- 
nation, but with petroleum they passed, probably forever, out of 
use, and it is more than likely that in respect to illumination we 
shall be independent of both animals and plants. 
Dependence of man upon animal labor. To harness the ani- 
mals and put them to work is one of the primitive instincts of 
Fic. 1. The famous Percheron stallion Brilliant 
After a painting by the great animal artist Rosa Bonheur 
man, and a book would be required even to outline the thou- 
sand ways in which man has been helped by his dumb com- 
panions, and in which his future happiness inevitably rests upon 
their labors, 
It is the reindeer and the dog that make the polar regions 
habitable. It was the ox that traveled the plains and developed 
the Pacific coast in the days of ’49. The last of the buffalo gave 
their flesh to feed the workmen that laid the Union Pacific — 
that first mechanical bond between the East and the West, 
