lc">B}

Pouchet’s observations on a change in the nests of swallows. 229 — Passage omitted about nest of Golden Crested Warbler, which had been inserted on Rennie’s authority, but has not been confirmed by any later observers. 261 261 Daines Barrington, on importance of protection to the female bird. 372 Note A. 372B Note B.

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CONTENTS.

1. On the Law which has regulated the introduction of New Species. Pp. 1-25
   
   • Geographical distribution dependent on Geologic Changes
   • A Law deduced from well-known Geographical and Geological facts
   • The form of a true system of Classification determined by this Law
   • Geographical Distribution of Organisms
   • Geological Distribution of the forms of Life
   • High Organization of very ancient Animals consistent with this Law
   • Objections to Forbes’ Theory of Polarity
   • Rudimentary Organs
   • Conclusion
2. On the Tendency of Varieties to depart indefinitely from the Original Type. Pp. 26-44
   
   • Instability of Varieties supposed to prove the permanent distinctness of Species
   • The Struggle for Existence
   • The Law of Population of Species
   • The Abundance or Rarity of a Species dependent upon its more or less perfect Adaptation to the Conditions of Existence
   • Useful Variations will tend to Increase, useless or hurtful Variations to Diminish
   • Superior Varieties will ultimately extirpate the Original Species
   • The Partial Reversion of Domesticated Varieties explained
   • Lamarck’s Hypothesis very different from that now advanced
   • Conclusion
3. Mimicry, and other Protective Resemblances among Animals. Pp. 45-129
   
   • Test of true and false Theories
   • Importance of the Principle of Utility
   • Popular Theories of Colour in Animals
   • Importance of Concealment as influencing Colour
   • Special modifications of Colour
   • Theory of Protective Colouring
   • Objection that Colour as being dangerous should not exist in Nature
   • Mimicry
   • Mimicry among Lepidoptera
   • Lepidoptera mimicking other