friend Hooker that he looked forward to "Down graveyard as the sweetest place on earth." Concerned about the book he had been anticipating for decades, he hurried his publisher John Murray to hasten publication of Worms even at the risk of not making a profit. At a dinner with Edward Aveling (soon the son-in-law of Karl Marx) and other atheists, he was asked how he had turned to such an "insignificant" subject as worms, to which he replied "I have been studying their habits for forty years." As with his religious views, the old naturalist did not see things the same way as Aveling. In Darwin's view, the "insignificant" was the foundation of much greater phenomena. Summary Worms are found in many places, from the forest floor to mountains, and in many locations around the world. Though they are considered terrestrial animals, they are really semi-aquatic, like other annelids; they die quickly in air but survive for months in water. Though inactive during the day, they sometimes come out of their burrows at night. They are eaten by thrushes and other birds in large numbers because they lie close to the surface. They have well developed muscular, nervous, circulatory and digestive systems, the latter being quite unique. Though eyeless, they respond to the intensity and duration of light. They also slowly respond to temperature. They have no hearing, but are sensitive to vibrations. Their sense of smell is feeble, but they are able to find their preferred foods. Omnivorous animals, they swallow much earth and extract food from it. Worms live chiefly on half decayed leaves, partially digested by a pancreatic solution before ingestion. This extra-stomachal digestion is not unlike that which Darwin had previously described as occurring in Insectivorous Plants. The structure and physiology of the calciferous glands of earthworms are described. Many hypotheses had been advanced for their function; Darwin believed them to be primarily for excretion and secondarily a digestion aid. Thin leaves are seized with the mouth, while thick ones are dragged by creating a vacuum. Leaves and stones are used to plug up the burrow. This may deter predators, keep out water and/or keep out chilled air (the latter is Darwin's preferred function). Leaves are dragged in mostly by the tips, which is the easiest way of doing it, but when the base is narrower the worms change behaviour. They drag pine needle clusters in