CONTENTS. ^ VII 



The experimental modification of color and color patterns — Continued. page 



Modification of color in L. signaticollis ; 209 



Temperature experiments 209 



Moisture experiments 211 



Modifications of color in other species of Lepiinotarsa 211 



General results derived from experimental modification of color 212 



Adaptation in coloration 215 



Warning coloration 215 



Protective resemblance 220 



The evolution of coloration 222 



Chapter IV.— Habits and Instincts in IvEptinotarsa. 



Habits and instincts connected with reproduction 229 



Mating habits 229 



Assortive mating ,. 238 



Number of generations 243 



Habits and instincts connected with hibernation and aestivation. 245 



Habits and instincts connected with self-preservation . . 252 



Chapter V. — Production in Experiment of Races, New Characters, 

 and Species in Leptinotarsa. 



Pedigree breeding of L. decenilineata 261 



Experiments in race production and modification by artificial selection 261 



Selection experiments with color characters , 261 



Selection experiments with structural characters 268 



Selection experiments with physiological characters 270 



Experimental pedigree breeding of new characters and species 271 



Pedigree breeding in L. multitcsniata . . 283 



Experiment in production of new characters and species 286 



Experiments with L. decemlineata 287 



Experiments with L. multitcBniata 292 



Experiments with L . undecimlineata 294 



Conclusion 294 



Chapter VI.— The Probi^em of the Origin oe Species— Discussion, 

 Summary, and Conci^usion. 



The method of evolution 298 



The nature, cause, and control of variation 298 



Mutation 307 



The origin of species 310 



BiBWOGRAPHY , . 315 



