On the Origin of Species by Means of Natural Selection: or the Preservation of Favoured Races in the Struggle for Life.… — Part 4 of 4

On the Origin of Species by Means of Natural Selection: or the Preservation of Favoured Races in the Struggle for Life. (2nd edition), by Charles Darwin. Part 4 of 4. Complete audiobook in 4 parts. Causes of Variability—Effects of Habit—Correlation of Growth—Inheritance—Character of Domestic Varieties—Difficulty of distinguishing between Varieties and Species—Origin of Domestic Varieties from one or more Species—Domestic Pigeons, their Differences and Origin—Principle of Selection anciently followed, its Effects—Methodical and Unconscious Selection—Unknown Origin of our Domestic Productions—Circumstances favourable to Man's power of Selection 7-43