CONTENTS. 



Page. 



Preface III-V 



THE PROBLEMS AND MATERIALS. 



Chapter L The Problems and Concepts of Evolution, 



Introduction I 



Physical Conception of Life 1 



Nature of the Individual 3 



Basis of Characters in Non-Living and Living Substances 5 



Relation of External and Internal Factors 5 



Categories of Organic Characteristics 6 



Evolution and Transmutation 8 



Hypotheses of Species Transmutation 11 



Processes of Evolution 18 



Factorial Theory of Evolution 21 



Chapter II. The Materials, Their Taxonomy and Natural History. 



Introduction 24 



Methods of Obtaining Materials 24 



Character and Source of Materials 25 



Species and Subdivisions of the Lineata Group 31 



Description of the Species 32 



Evolution and Phylogeny of the Lineata Group 69 



Chapter III. The Problems of Gametic Constitution. 



Introduction 72 



The Germ-plasm Concept 76 



The Gametic Agents 78 



Metathesis of Gametic Agents 80 



Architecture of the Germinal Material 83 



Chapter IV. Reactions and Products in Interspecific Crosses. 



Methods of Culture 90 



Leptinotarsa signaticollis X L. diversa 94 



Leptinotarsa undecimlineata X L, signaticollis 124 



Leptinotarsa undecimlineata X L. diversa 142 



Discussion of the Results Derived in Crossing the Species L. diversa, L. sig- 

 naticollis, and L. undecimlineata 143 



Chapter V. Reactions and Products in I^^terspecific Crosses. 



Leptinotarsa diversa X L. decemlineata 146 



Leptinotarsa decemlineata X L. oblongata 152 



Leptinotarsa decemlineata X L. multita:niata 163 



Leptinotarsa multitwniata X L. oblongata 168 



Summary and Discussion of the Crossing of Species 169 



Chapter VI. The Problems of Heterogeneity. 



Introduction 184 



Problems of Heterogeneity 185 



Causes of Heterogeneity 190 



Analysis of Heterogeneity 191 



VII 



