Variation Under Domestication

Causes of Variability — Effects of Habit and the use and 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, anciently followed, their Effects — Methodical and Unconscious Selection — Unknown Origin of our Domestic Productions — Circumstances favourable to Man’s power of Selection.

1. Causes of Variability

When we compare the individuals of the same variety or sub-variety of our older cultivated plants and