Species, permanence of, 9; some benefited by change of habitat, 21; variations of, how advantageous, 27; difficulty of collecting all for the Ark, 43; distribution of, 45. Spencer, Mr. Herbert, his caution about embryonic forms, 19, _note_; his accurate phrase, ‘Survival of the fittest,’ 154; his ‘Principles of Biology,’ 161. Sponges, not to be hurried, 117; range of in geology, 136; final cause of, 138. Stalagmite, thickness of in Kent’s cavern, 110; time required for forming, 113; dates carved upon, 115. Stratification, uniform order of, 116, 122. Struggle for life, 11; great fecundity useful to a species in, 24. Sylvia Sutoria, the tailor-bird, its nest, 29. Tails, rudimentary, in man, 22, 155. Tennyson, language of ‘the Brook’ in, 125. Theories, when to be accepted, 18. Thought, time required for, 64; movement of, depending on language, 87. Time, immense duration of, required by the Theory of Natural Selection, 30, 67; lapse of, 93-125; (see _Earth_, age of); inexhaustible, 98, 125. Tinière, delta of, 107. Tyndal, Professor, on ‘The Minuteness of Waves of Light,’ 97. Usher, archbishop, Bible-chronology of, 99, 110. Variability, 7; objection to, considered, 128. Vertebrate, the first, how originated, 158; type of, supposed to be connected with cuttle-fish, 161; definition of, investigated, 161. Vivian, Mr., exploration of Kent’s cavern by, 109. Wallace, Mr., his originality recognized, 5; his opinion of the limits of Natural Selection, 62; his exposure of fallacious views about Instinct, 67; his theory of birds’ nests, 69; his comparison of birds with men as builders, 70; his speculation about the brain of the savage, 78. War, in the animal and vegetable kingdoms, 12; combination of baboons for, 69; comparison of man and other animals engaged in, 86. Wasps, their defensive weapon, 25; materials used by, 86. Whewell, Dr., his remark on Scientific Phraseology, 160. Writing, invention of, 103. Transcriber’s Notes The cover of this eBook was made by the Transcriber, by combining the original Title Page and the blank green cover provided with the printed book. The result remains in the Public Domain. Punctuation, hyphenation, and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed. Simple typographical errors were corrected; occasional unbalanced quotation marks remedied. Ambiguous hyphens at the ends of lines were retained. Footnotes, originally at the bottoms of pages, have been collected and repositioned after the last chapter of the book, just before the Index. Index not checked for proper alphabetization or correct page references. Page 3: “One” was capitalized in “qualified, One, without doubt”. End of Project Gutenberg's Essays on Darwinism, by Thomas R. R. Stebbing