CHAPTER III. STRUGGLE FOR EXISTENCE. Its bearing on natural selection-The term used in a wide sense CHAPTER IV. NATURAL SELECTION. - .. Page 63-82 Natural Selection-its power compared with man's selection - its CHAPTER V. LAWS OF VARIATION. Effects of external conditions-Use and disuse, combined with - CHAPTER VI. DIFFICULTIES ON THEORY, - Difficulties on the theory of descent with modification-Transitions- CHAPTER VII. INSTINCT. Instincts comparable with habits, but different in their origin. - - Domestic instincts, their origin-Natural instincts of the cuckoo, -- 227-266 CHAPTER VIII. HYBRIDISM. - Distinction between the sterility of first crosses and of hybrids — - 267-301 CHAPTER IX. ON THE IMPERFECTION OF THE GEOLOGICAL RECORD. - On the absence of intermediate varieties at the present day - On CHAPTER X. ON THE GEOLOGICAL SUCCESSION OF ORGANIC BEINGS. - On the slow and successive appearance of new species-On their CHAPTER XI. GEOGRAPHICAL DISTRIBUTION. - 338-375 Present distribution cannot be accounted for by differences in phy- CHAPTER XII. GEOGRAPHICAL DISTRIBUTION-continued. Distribution of fresh-water productions - On the inhabitants of CHAPTER XIII. MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY: CLASSIFICATION, groups subordinate to groups - Natural system- ·Affinities, general, complex and radiating-Extinction se- - - favour CHAPTER XIV. RECAPITULATION AND CONCLUSION. Recapitulation of the difficulties on the theory of Natural Selection INDEX 492-525 -527-538 |