No one can read Darwin's _Journal_ descriptive of the voyage of the Beagle and continue to entertain any doubts in reference to his æsthetic sense and poetic appreciation of the various moods of nature. Throughout the voyage the scenery was for him the most constant and highest source of enjoyment. His emotions responded to the glories of tropical vegetation in the Brazilian forests, and to the sublimity of Patagonian wastes and the forest-clad hills of Tierra del Fuego. "It is easy," writes the gifted adolescent, "to specify the individual objects of admiration in these grand scenes; but it is not possible to give an adequate idea of the higher feelings of wonder, astonishment, and devotion, which fill and elevate the mind." Similarly, on the heights of the Andes, listening to the stones borne seaward day and night by the mountain torrents, Darwin remarked: "The sound spoke eloquently to the geologist; the thousands and thousands of stones, which striking against each other, made the one dull uniform sound, were all hurrying in one direction. It was like thinking on time, where the minute that now glides past is irrecoverable. So was it with these stones, the ocean is their eternity, and each note of that wild music told of one more step towards their destiny." When the Beagle left Devonport, December 27, 1831, the young naturalist was without any theory, and when the ship entered Falmouth harbor, October 2, 1836, though he felt the need of a theory in reference to the relations of the various species of plants and animals, he had not formulated one. It was not till 1859 that his famous work on the _Origin of Species_ appeared. He went merely as a collector, and frequently in the course of the voyage felt a young man's misgivings as to whether his collections would be of value to his Cambridge professors and other mature scientists.