—Third edition, with additions and corrections. (Seventh thousand.) 8vo. London, 1861. (Dated March, 1861.)
—Fourth edition with additions and corrections. (Eighth thousand.) 8vo. London, 1866. (Dated June, 1866.)
—Fifth edition, with additions and corrections. (Tenth thousand.) 8vo. London, 1869. (Dated May, 1869.)
—Sixth edition, with additions and corrections to 1872. (Twenty-fourth thousand.) 8vo. London, 1882. (Dated January, 1872.)
On the various contrivances by which Orchids are fertilised by Insects. 8vo. London, 1862.
—Second edition. 8vo. London, 1877. [In the second edition the word "On" is omitted from the title.]
The Movements and Habits of Climbing Plants. Second edition. 8vo. London, 1875. [First appeared in the ninth volume of the 'Journal of the Linnean Society.']
The Variation of Animals and Plants under Domestication. 2 volumes. 8vo. London, 1868.
—Second edition, revised. 2 volumes. 8vo. London, 1875.
The Descent of Man, and Selection in Relation to Sex. 2 volumes. 8vo. London, 1871.