Discusses the Duke of Argyll’s book [Reign of law (1867)].

Cites his own views on diversity of structure and beauty.

Encloses letter from Wallace. Sexual selection: evidence advanced by Wallace.

Discusses correlation of growth.

Comments on article in the North British Review [by Fleeming Jenkin].

Discusses the evidence from physics on the age of the earth.

[Four pages of the final letter are missing, but the draft is complete.]