Species and Varieties, Their Origin by Mutation

Species and Varieties, Their Origin by Mutation, written by Dutch botanist Hugo de Vries in the early 20th century, presents a scientific exploration of mutation theory as a mechanism for the origin of species and varieties. De Vries challenges the gradual change model of evolution proposed by Darwin, advocating for the idea that new species arise suddenly through mutations. The book emphasizes the importance of empirical research and controlled experiments in understanding plant evolution, critiquing existing theories of descent and laying the groundwork for future studies in genetics and horticulture.