On the Spanish Main; Or, Some English forays on the Isthmus of Darien
On the Significance of Science and Art
On the Seashore
On the Ruin of Britain
On the right of the British line
On the Relations of Man to the Lower Animals
On the Red Chalk of England
On the Reception of the 'Origin of Species'
On the Prospects of Christianity
On The Principles of Political Economy, and Taxation
On the Portraits of English Authors on Gardening,
On the Plantation: A Story of a Georgia Boy's Adventures during the War
On the Phenomena of Hybridity in the Genus Homo
On the Pampas; Or, The Young Settlers
On the Origin of Species
On the Origin of Species By Means of Natural Selection