The Origin of Species

CHAPTER II Variability – Individual differences – Doubtful species – Wide ranging, much diffused, and common species, vary most – Species of the larger genera in each country vary more frequently than the species of the smaller genera – Many of the species of the larger genera resemble varieties in being very closely, but unequally, […]

CHAPTER I Causes of variability – Effects of habit and the use or disuse of parts – Correlated variation – 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 – Principles of selection,