Famous quotes containing the words biological and/or shield:
“Although there is no universal agreement as to a definition of life, its biological manifestations are generally considered to be organization, metabolism, growth, irritability, adaptation, and reproduction.”
—The Columbia Encyclopedia, Fifth Edition, the first sentence of the article on “life” (based on wording in the First Edition, 1935)
“The lichen on the rocks is a rude and simple shield which beginning and imperfect Nature suspended there. Still hangs her wrinkled trophy.”
—Henry David Thoreau (1817–1862)