EARTHSHINE. The earth is a luminary to the moon as the moon is to the earth ; consequently the portion of the moon's disc which is not illuminated by the sun is illuminated by earth shine analogous to moonlight. It is a familiar observation that when the moon is a crescent the earthshine is powerful enough to make the whole disc easily visible. The phases of the earth and moon are complementary, so that the earth is near "full" when the moon is near "new" and the earthshine is then strongest.
(Geaster), in botany, a kind of puff-ball (q.v.), with a distinct outer coat which, on separating from the inner, splits into several divisions, which become reflexed and spread like a star. The inner coat enveloping the spores is sup ported, like a ball, with or without a stalk on the upper face of the star. The spores generally escape by a distinct aperture which appears in the top of the ball. There are several species in Britain, found on the ground or on decaying leaves. They are rare or local, but fairly common in south or south-east England. (See FUNGI.) EARTHWORM, the name of oligochaete worms found nearly all over the world. There are now more than I,000 species known and the number is increasing. The earthworms of England belong almost entirely to the family Lumbricidae, which forms the prev alent earthworm fauna of the Palaearctic region and is also strongly represented in the Nearctic. Elsewhere they are replaced by the numerous genera of the families enumerated in the article ANNELIDA (q.v.). It is a remarkable fact that members of the family Lumbricidae, when introduced into tropical and other coun tries, thrive abundantly and oust the indigenous forms. In gath erings of earthworms from various extra-European countries it is always found that the worms of the cultivated ground and that near the coast are European species, the native forms being met with farther inland. The Lumbricidae from non-Palaearctic countries are mostly identical with Palaearctic species; and since they are impatient of sea-water, it seems clear that they must have been accidentally transported with plants, etc. Most earth worms live in the soil, which they devour as they burrow through it. A few, like their allies the river worms (Limicolae), habitually frequent streams, lakes, etc. Truly oceanic islands have no in digenous earthworm fauna, but are inhabited by forms identical with those of neighbouring continents, accidentally introduced.
Earthworms are hermaphrodite. Like the leeches (q.v.) they produce cocoons which are a product of the glandular epithelium of the clitellum. In pairing, earthworms come together with the head of one directed towards the tail of the other. The spermato zoa are then exchanged, passing into the spermatliecae of the part ner, whence they are transferred to the cocoon as the latter passes forward over the head. In these cocoons are previously deposited the eggs together with albumen upon which the embryos feed. So far as is known, the production of cocoons is universal among the Oligochaeta. The young hatch as fully formed earthworms. The work of earthworms in aiding the production of subsoil and in levelling the surface was first studied by Darwin, and has since been investigated by others. This work is partly carried out be neath the surface and partly on the surface, upon which the worms wander at night and eject the swallowed and triturated earth. Frequently castings of some height are formed of coiled ropes of agglutinated particles of mould. The British species, between 30 and 4o in number, do not grow to a greater length than loin.; but in tropical countries there are species which reach a length of 4f t. Thus we have in Natal the gigantic Microchaetus microchaetus; in southern India, Drawida grandis; in Australia, Megascolides australis; and in South America, Glossoscolex giganteus. See ANNELIDA : Oligochaeta.
See Darwin, Formation of Vegetable Mould by Action of Earth worms; F. Beddard, Earthworms and their Allies.