Encloses letter concerning Edward Blyth’s application for a position with the China expedition.

Mentions reviews of the Origin. Guesses that Huxley wrote the Times review.

Alludes to discussion of relations between fossil and modern types [in Principles of geology 3: 144].

Discusses destruction of tropical forms in the glacial period.

Mentions letter from Dana concerning Dana’s illness.

CL’s comments on Origin. Mentions corrections to last chapter suggested by CL.

Comments on lack of peculiar bird species on Madeira and Bermuda. Emphasises importance of American types in Galapagos.

Denies necessity of continued creation of primitive "Monads".

Denies need for new powers and any principle of improvement.

Discusses gradations of intellectual powers.

Adaptive inferiority and extinction of groups of species and genera.

Asserts that climate is less important than the struggle with other organisms.

Suggests an experiment involving primroses and cowslips.

The chapter on hybridisation.

Rudimentary organs.

Gives opinion of Lamarck’s work.