The Nature of Floating Life--Memoir on Medusæ Accepted by the Royal Society--Old and New Ideas of the Animal Kingdom--What Huxley Discovered in Medusæ--His Comparison of them with Vertebrate Embryos CHAPTER IV EARLY DAYS IN LONDON 46 Scientific Work as Unattached Ship-Surgeon--Introduction to London Scientific Society--Translating, Receiving, and Lecturing--Ascidians--Molluscs and the Archetype--Criticism of Pre-Darwinian Evolution--Appointment to Geological Survey. CHAPTER V CREATURES OF THE PAST 67 Beginning Palæontological Work--Fossil Amphibia and Reptilia--Ancestry of Birds--Ancestry of the Horse--Imperfect European Series Completed by Marsh's American Fossils--Meaning of Geological Contemporaneity--Uniformitarianism and Catastrophism Compared with Evolution in Geology--Age of the Earth--Intermediate and Linear Types. CHAPTER VI HUXLEY AND DARWIN 89 Early Ideas on Evolution--Erasmus Darwin--Lamarck--Herbert Spencer--Difference between Evolution and Natural Selection--Huxley's Preparation for Evolution--The Novelty of Natural Selection--The Advantage of Natural Selection as a Working Hypothesis--Huxley's Unchanged Position with regard to Evolution and Natural Selection from 1860 to 1894. CHAPTER VII THE BATTLE FOR EVOLUTION 110 Huxley's Prevision of the Battle--The Causes of the Battle--The _Times_ Review--Sir Richard Owen attacks Darwinism in the _Edinburgh Review_--Bishop Wilberforce attacks in the _Quarterly Review_--Huxley's Scathing Replies--The British Association Debates at Oxford--Huxley and Wilberforce--Résumé of Huxley's Exact Position with Regard to Evolution and to Natural Selection. CHAPTER VIII VERTEBRATE ANATOMY 128 The Theory of the Vertebrate Skull--Goethe, Oken, Cuvier, and Owen--Huxley Defends Goethe--His own Contributions to the Theory--The Classification of Birds--Huxley Treats them as "Extinct Animals"--Geographical Distribution--Sclater's Regions--Huxley's Suggestions. CHAPTER IX MAN AND THE APES 144 Objections to Zoölogical Discussion of Man's Place--Owen's Prudence--Huxley's Determination to Speak out--Account of his Treatment of _Man's Place in Nature_--Additions Made by More Recent Work. CHAPTER X SCIENCE AS A BRANCH OF EDUCATION 167 Science-Teaching Fifty Years Ago--Huxley's Insistence on Reform--Science Primers--Physiography--Elementary Physiology--_The Crayfish_--Manuals of Anatomy--Modern Microscopical Methods--Practical Work in Biological Teaching--Invention of the Type System--Science in Medical Education--Science and Culture. CHAPTER XI