Music, Darwin's loss of power to appreciate, and its cause, [134], [135]
Natural Selection, theory of, defined by Huxley, [106];
forestalled by Wells, Matthew &c., [18], [19];
first conception of by Darwin, [107];
by Wallace, [112]
'Neptunism' or 'Wernerism' and Catastrophism, [18]
Newton, Professor A., on vague hopes of solution of 'species question' before Darwin, [94], [109]
Origin of Species, first idea of, [121];
plan proposed to follow Principles, [123];
first sketch of 1842, enlarged draft of 1844, commencement of great treatise on Evolution in 1856, interruption by arrival of Wallace's papers, [128], [129];