XI 1 



CONTENTS OF THE SECOND VOLUME. 



CHAPTER XXXV. 



THEORIES AS TO THE NATURE OF SPECIES, AND DARWIN ON NATURAL 



SELECTION. 



Objections urged against the Theory of Transmutation and Lamarck's Eeplies^ 

 Mummies of Animals and Seeds of Plants from Egyptian Tombs identical * 

 Character with Species now living— Linnseus's Opinion that Species have been 

 Constant since their Creation— Brocchi's Hypothesis of the Gradual Diminution 

 of Vital Power in a Species— Whether if New Species are created from Time 

 to Time their Eirst Appearance must have been witnessed by the Naturahst— • 

 GeofFroy St. Hilaire and Lamarck on Eudimentary Organs — The Question of 

 Species as treated of in the ' Vestiges of Creation ' — Mr. Alfred Wallace on the 

 Law which has regulated the Introduction of New Species— Mr. Darwin on 

 Natural Selection, and Mr. Wallace on the same— Darwin's Origin of Species 

 and the Change of Opinion which it effected— Dr. Hooker's Flora of Austraha' 

 and his Views as to the Origin of Species by Variation . 



PAGE 261 



CHAPTER XXXVI. 



VARIATION OF PLANTS AND ANIMALS UNDER DOMESTICATION VIEWED AS 



BEARING ON THE ORIGIN OF SPECIES. 



Domestic races, however Divergent, breed freely together—Eemote Antiquity 

 of some artificially formed Eaces— Selection, both Unconscious and Methodi- 

 cal, very influential in forming New Eaces— The Characters of some Eaces of 

 the Domesticated Pigeon of generic Value— Eevival of long-lost Characters in 

 the Offspring of Cross-breeds— Multiple Origin of the Dog— Inherited Instincts 

 —Variation of the Gold Fish and Silkworm— Man causes particular Parts of an 

 Animal or Plant to vary while other Parts continue unaltered— Maize— Cab- 

 bage— Are there any Limits to the Variability of a Species ?— Obedience to 

 Man under Domestication often merely a new Adaptation of a Natural Instinct 

 —' Feral ' Varieties do not revert to the exact Likeness of the Original Wild 

 Stock— How far do Domestic Eaces differ from Wild Species in their Capacity 

 to Inter-breed ?— Hybridisation of Animals and Plants — Hermaphrodite 

 Plants not usually self-fertilised— Whether the Distinctness of Species can be 

 tested by Hybridity— Tendency of different Eaces of Domestic Cattle and 

 Sheep to herd apart— Pallas on Domesticity eliminating Sterility— Correlation 



of Growth 



284 



CHAPTEE XXXVII. 



NATURAL SELECTON. 



Natural as compared to Artificial Selection— Tendency in each Species to multi- 

 ply beyond the Means of Subsistence— Terms * Selection ' and 'Survival of the 

 Fittest '—Great Number and Variety of the Natural Conditions of Existence on 

 which the Constancy or Variation of a Species depends— Acclimatisation of 

 Species— The Intercrossing of slight Varieties beneficial— Breeding in and in 

 injurious— Wild Hybrid Plants, and Opinions of Linn^us on Protean Genera 

 -De CandoUe on Wild Hybrids— Hybridity will not account for Special In- 

 stincts— The Species of Polymorphous Genera more variable and comparatively 

 Modern— Alternate Generation does not explain the Origin of New Species 316 



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