The article discusses how Charles Darwin's children drew on the manuscript of his book 'On the Origin of Species', providing a glimpse into the family life of the famous naturalist. The drawings, found on the back of the manuscript, include a battle scene between fruit and vegetable soldiers and a depiction of the Darwin family home. The article also explores Darwin's personal life, including his marriage to his cousin Emma and his thoughts on having children. The drawings and other personal documents are available online through the Darwin Manuscripts Project and Darwin Online.