What was the title of Charles Darwin's 1868 book on domesticated plants and animals?

Charles Darwin’s 1868 book on domesticated plants and animals was The Variation of Animals and Plants Under Domestication.

Published in two volumes by John Murray, the book examined how selective breeding produced variation in species such as dogs, pigeons, horses, cattle, poultry, and cultivated plants. Darwin used these examples to support his broader argument that populations could change over generations.

The work grew out of research Darwin had begun after On the Origin of Species. He devoted particular attention to pigeons because their dramatic differences showed how breeders could reshape a species from inherited variation. The book also introduced his speculative theory of heredity, called pangenesis.

It is sometimes confused with The Descent of Man, published in 1871, or The Expression of the Emotions in Man and Animals, published in 1872. Those later books dealt more directly with human evolution and behavior, while the 1868 work focused on variation under domestication.