Advancement of the intellectual powers through natural selection--
Importance of imitation--Social and moral faculties--Their development
within the limits of the same tribe--Natural selection as affecting
civilised nations--Evidence that civilised nations were once barbarous.


CHAPTER VI.

On the Affinities and Genealogy of Man.

Position of man in the animal series--The natural system genealogical--
Adaptive characters of slight value--Various small points of resemblance
between man and the Quadrumana--Rank of man in the natural system--
Birthplace and antiquity of man--Absence of fossil connecting-links--Lower
stages in the genealogy of man, as inferred firstly from his affinities and
secondly from his structure--Early androgynous condition of the Vertebrata
--Conclusion.


CHAPTER VII.

On the Races of Man.

The nature and value of specific characters--Application to the races of
man--Arguments in favour of, and opposed to, ranking the so-called races of
man as distinct species--Sub-species--Monogenists and polygenists--
Convergence of character--Numerous points of resemblance in body and mind
between the most distinct races of man--The state of man when he first
spread over the earth--Each race not descended from a single pair--The
extinction of races--The formation of races--The effects of crossing--