Famous quotes containing the words single and/or species:
“It may seem strange that any road through such a wilderness should be passable, even in winter, when the snow is three or four feet deep, but at that season, wherever lumbering operations are actively carried on, teams are continually passing on the single track, and it becomes as smooth almost as a railway.”
—Henry David Thoreau (1817–1862)
“The principle of avoiding the unnecessary expenditure of energy has enabled the species to survive in a world full of stimuli; but it prevents the survival of the aristocracy.”
—Rebecca West (1892–1983)