Louis Agassiz Quotes about Nature
Louis Agassiz (1857). “Contributions to the Natural History of the United States of America: pt. I. Essay on classification. pt. II. North American Testudinata. 1857”, p.139
"Geological Sketches". Book by Louis Agassiz, ch. 2 (pp. 31 - 32), 1870.
Louis Agassiz (2003). “Agassiz on Evolution: Methods of study in natural history”