TABLE OF CONTENTS 



PAOE 



Introduction i 



CHAPTER 



I. Man and Animals 5 



I. Introduction 5 



II. The Struggle in Nature 6 



III. Man's Relation to Nature : . . . 8 



IV. The Economic Importance of Animals 20 



II. The Animal Organism and Its Environmental Relations 22 



I. Nature of Living Substance 22 



II. The Relation of Form or Structure to Function .... 22 



III. The Basis for the Organization of Ecology 23 



IV. Scope and Meaning of Ecology 32 



V. Communities and Biota S3 



III. The Animal Environment: Its General Nature and Its 

 Character in the Area of Study 42 



I. Nature and Classification of Environments 42 



II. The Important Factors and Their Control in Nature . . 43 



III. History of the Region about Lake Michigan .... 44 



IV. Extent and Topography of the Area Considered ... 48 

 V. Climate and Vegetation of the Area 49 



VI. Localities of Study (Guide) 50 



VII. Legal Aspects of Field-Study 56 



IV. Conditions of Existence of Aquatic Animals .... 58 



I. Introduction: Comparison of Land and Aquatic Animals 58 



II. Chemical Conditions 58 



III. Physical Conditions 60 



IV. Elementary Food Substances 65 



V. Quantity of Life in Water 67 



V. Animal Communities of Large Lakes (Lake Michigan) . 73 



I. Conditions 73 



II. Communities of the Lake 73 



III. Summary 81 



VI. Animal Communities of Streams 86 



I. Introduction 86 



II. Communities of Streams 86 



III. Special Stream Problems 105 



xi 



