CONTENTS

PAGE
STROMNESS AND ITS ASTEROLEPIS.—THE LAKE OF STENNIS 21
THE DEVELOPMENT HYPOTHESIS, AND ITS CONSEQUENCES 37
THE RECENT HISTORY OF THE ASTEROLEPIS.—ITS FAMILY 48
CEREBRAL DEVELOPMENT OF THE EARLIER VERTEBRATA.—ITS APPARENT PRINCIPLE 62
THE ASTEROLEPIS.—ITS STRUCTURE, BULK, AND ASPECT 94
FISHES OF THE SILURIAN ROCKS, UPPER AND LOWER.—THEIR RECENT HISTORY, ORDER, AND SIZE 130
HIGH STANDING OF THE PLACOIDS.—OBJECTIONS CONSIDERED 147
THE PLACOID BRAIN.—EMBRYONIC CHARACTERISTICS NOT NECESSARILY OF A LOW ORDER 160
THE PROGRESS OF DEGRADATION.—ITS HISTORY 181
EVIDENCE OF THE SILURIAN MOLLUSCS.—OF THE FOSSIL FLORA.—ANCIENT TREE 205
SUPERPOSITION NOT PARENTAL RELATION.—THE BEGINNINGS OF LIFE 230
LAMARCKIAN HYPOTHESIS OF THE ORIGIN OF PLANTS.—ITS CONSEQUENCES 243
THE TWO FLORAS, MARINE AND TERRESTRIAL.—BEARING OF THE EXPERIENCE ARGUMENT 262
THE DEVELOPMENT HYPOTHESIS IN ITS EMBRYONIC STATE.—OLDER THAN ITS ALLEGED FOUNDATIONS 277
FINAL CAUSES—THEIR BEARING ON GEOLOGIC HISTORY—CONCLUSION 303