Quotes from Jean Baptiste Lamarck

first law. In every animal… a more frequent and continuous use of any organ gradually strengthens, develops and enlarges that organ… while the permanent disuse of any organ imperceptibly weakens and deteriorates it, and progressively diminishes its functional capacity, until it finally disappears.second law. All the acquisitions or losses wrought by nature in individuals… are preserved by reproduction to the new individuals which arise.

Habits form a second nature.