Our supreme American example of this life in nature, and perhaps the supreme example anywhere, is Henry Thoreau. Thoreau had his speculations, and some persons relish them. But it seems as if no other human being had ever left the record of such complete self-abnegation in the external world as Thoreau’s. His soul not only turns to that of the birds and flowers, it is that of the birds and flowers, and he is never, never making observations to serve a purpose. He is simply existing in the universal existence for the joy of it: ‘I have given myself up to nature; I have lived so many springs and summers and autumns and winters as if I had nothing else to do but _live_ them, and imbibe whatever nutriment they had for me; I have spent a couple of years, for instance, with the flowers chiefly, having none other so binding engagement as to observe when they opened; I could have afforded to spend a whole fall observing the changing tints of the foliage. Ah, how I have thriven on solitude and poverty!’[6] II Of the numerous records of simple natural observation and experience few are more charming than Darwin’s ‘Journal of the Voyage of the Beagle,’ in which he notes what he saw and heard by land and sea during those years of adventure in the southern hemisphere. All through this book, as indeed in all his books, it is evident that the instinct and habit of observing were inborn and constant, and all those who write about Darwin make this instinct at least the foundation of his scientific eminence. [Illustration: THE BEAGLE LAID ASHORE FOR REPAIRS AT RIVER SANTA CRUZ, PATAGONIA] Asa Gray, who had given his life to botany, writes: ‘What a skill and genius you have for these researches! Even for the structure of the flower of the Ophyrideæ I have to-night learned more than I ever knew before.’[7] Professor Osborn says, more generally: ‘Rare as were his reasoning powers, his powers of observation were of a still more distinct order. He persistently and doggedly followed every clue; he noticed little things which escaped others; he always noted exceptions and at once jotted down facts opposed to his theories.’[8] And the editors of Darwin’s letters put the whole matter with concise effectiveness in speaking of ‘that supreme power of seeing and thinking what the rest of the world had overlooked, which was one of his most striking characteristics.’[9]