Horrabin he has had the good fortune to find not only an illustrator but a collaborator. Mr. Horrabin has spared no pains to make this work informative and exact. His maps and drawings are a part of the text, the most vital and decorative part. Some of them, the hypothetical maps, for example, of the western world at the end of the last glacial age, during the “pluvial age” and 12,000 years ago, and the migration map of the Barbarian invaders of the Roman Empire, represent the reading and inquiry of many laborious days. The index to this edition is the work of Mr. Strickland Gibson of Oxford. Several correspondents have asked for a pronouncing index and accordingly this has been provided. The writer owes a word of thanks to that living index of printed books, Mr. J. F. Cox of the London Library. He would also like to acknowledge here the help he has received from Mrs. Wells. Without her labour in typing and re-typing the drafts of the various chapters as they have been revised and amended, in checking references, finding suitable quotations, hunting up illustrations, and keeping in order the whole mass of material for this history, and without her constant help and watchful criticism, its completion would have been impossible. [Illustration: H. G. Wells] SCHEME OF CONTENTS BOOK I THE MAKING OF OUR WORLD PAGE CHAPTER I. THE EARTH IN SPACE AND TIME 3 CHAPTER II. THE RECORD OF THE ROCKS § 1. The first living things 7 § 2. How old is the world? 13 CHAPTER III. NATURAL SELECTION AND THE CHANGES OF SPECIES 16 CHAPTER IV. THE INVASION OF THE DRY LAND BY LIFE § 1. Life and water 23 § 2. The earliest animals 25 CHAPTER V. CHANGES IN THE WORLD’S CLIMATE § 1. Why life must change continually 29 § 2. The sun a steadfast star 34 § 3. Changes from within the earth 35 § 4. Life may control change 36 CHAPTER VI. THE AGE OF REPTILES § 1. The age of lowland life 38 § 2. Flying dragons 43 § 3. The first birds 43 § 4. An age of hardship and death 44 § 5. The first appearance of fur and feathers 47 CHAPTER VII. THE AGE OF MAMMALS § 1. A new age of life 51 § 2. Tradition comes into the world 52 § 3. An age of brain growth 56