Originally published during the early part of the twentieth century, the Cambridge Manuals of Science and Literature were designed to provide concise introductions to a broad range of topics. They were written by experts for the general reader and combined a comprehensive approach to knowledge with an emphasis on accessibility. Plant-Animals by Frederick Keeble was first published in 1910. The volume presents an account of the nature and behaviour of Convoluta roscoffensis and Convoluta paradoxa, two types of marine worm.