x Contents. 



CHAPTER VI. 



PACK 



CHARACTERS AS HEREDITARY AND ACQUIRED (Conclusion) 150 



CHAPTER VII. 

 CHARACTERS AS ADAPTIVE AND SPECIFIC . . . .159 



CHAPTER VIII. 



CHARACTERS AS ADAPTIVE AND SPECIFIC (Continued). 



I. Climate aoo 



II. Food 217 



III. Sexual Selection 219 



IV. Isolation . 223 



V. Laws of Growth 226 



CHAPTER IX. 

 CHARACTERS AS ADAPTIVE AND SPECIFIC (Continued} . . 328 



CHAPTER X. 



CHARACTERS AS ADAPTIVE AND SPECIFIC (Concluded') . .251 

 SUMMARY 274 



APPENDIX I. ON PANMIXIA 291 



APPENDIX II. ON CHARACTERS AS ADAPTIVE AND SPECIFIC . 307 



NOTE A TO PAGE 57 333 



NOTE B TO PAGE 89 337 



