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species of earthworm and named it Lumbricus terrestris. There are now one thousand well-characterized species known from different parts of the world, and the number increases almost daily. The earthworms of See also:

England belong entirely to the three genera Lumbricus, Allolobophora and Allurus, which are further subdivided by some systematists; and these genera See also:

FORM (Lat. forma)

form the prevalent earthworm See also:

FAUNA

fauna of the Palaearctic region and are also very numerous in the Nearctic region. Elsewhere they do not appear to be indigenous, but are replaced by the numerous other genera of the families enumerated in the See also:

ARTICLE (from Lat. articulus, a joint)

article See also:

CHAETOPODA (Gr. xairq, hair, aous, foot)

Chaetopoda (q.v.). It is a remarkable fact that these genera, comprizing a See also:

SEPARATE

separate See also:

FAMILY

family Lumbricidae, when introduced into tropical and other countries, thrive abundantly and oust the indigenous forms. In gatherings of earthworms from various extra-See also:

EUROPEAN

European countries it is always found that if the collections have been made in cultivated ground and near the See also:

COAST (from Lat. costa, a rib, side)

coast the See also:

WORMS

worms are of European species; farther inland the native forms are met with. Inasmuch as in every See also:

case the Lumbricidae from non-Europeancountries are identical with European species, since it has been shown that these animals are very readily introduced accidentally with See also:

PLANTS

plants, &c., and in view of the fact that they are impatient of See also:

sea See also:

WATER

water, it seems clear that the presence of these Lumbricidae in other continents is due to accidental transportation. Most earthworms live in the See also:

SOIL

soil, which they devour as they burrow through it. A few, like their See also:

ALLIES, THOMAS WILLIAM (1813-1903)

allies the See also:

RIVER

river worms (Limicolae), habitually frequent streams, lakes, &c. One genus, at any See also:

RATE

rate, viz. Pontodrilus, seeks an unusual environment, and is found in heaps of sea-See also:

WEED, THURLOW (1797—1882)

weed See also:

CAST (from the verb meaning " to throw "; the word is Scand. in origin, cf. Dan. kaste, and Swed. kasta; " cast " in Middle Eng. took the place of the A.S. weor pan, cf. Ger. werf en)

cast up by the sea.

The range of this genus is therefore naturally wider than that of other genera which are confined to See also:

LAND

land masses and cannot See also:

CROSS

cross the sea by their own efforts. It might be inferred, therefore, and the inference is proved by facts, that truly oceanic islands have no indigenous fauna of earthworms, but are inhabited by forms which are identical with those of neighbouring continents, and doubtless, therefore, accidentally introduced. Like the leeches the earthworms produce cocoons which are a product of the glandular epithelium of the clitellum. In these cocoons are deposited the eggs together with a certain amount of albumen upon which the developing embryos feed. So far as is known, the See also:

PRODUCTION (Lat. productionem, from producere, to pro-duce)

production of cocoons is universal among earthworms and the remaining See also:

OLIGOCHAETA

Oligochaeta of aquatic See also:

HABIT (through the French from Lat. habitus, from habere, to have, hold, or, in a reflective sense, to be in a certain condition; in many of the English senses the French use habitude, not habit)

habit. The See also:

young leave the cocoon as fully formed earthworms in which, however, the genitalia are not fully See also:

DEVELOPED

developed. There is no See also:

FREE

free living larval See also:

STAGE (Fr. 6/age; from Lat. stare, to stand)

stage. Out of a single cocoon emerge a varying number of young worms, the See also:

numbers being apparently characteristic of the species. The See also:

WORK

work of earthworms in aiding in the production of the subsoil and in levelling the See also:

SURFACE

surface was first studied by C. See also:

Darwin, and has since been investigated by others. This work is partly carried out beneath the surface and partly on the surface, upon which the worms wander at See also:

NIGHT

night and eject the swallowed and triturated See also:

earth; frequently castings of some height are formed of coiled See also:

ROPES, JOHN CODMAN (1836–1899)

ropes of agglutinated particles of See also:

MOULD

mould. The indigenous species of See also:

GREAT

Great See also:

BRITAIN (Gr. Hperavuml vi7vot, Bperravia; Lat. Britannia, rarely Britannia)

Britain, about twenty in number, do not grow to a greater length than some ro in.; but in several tropical countries there are species which grow to a length of from 3 to 6 ft.

Thus we have in See also:

NATAL

Natal the gigantic Microchaeta rappi, in See also:

CEYLON

Ceylon Megascolex coeruleus, in See also:

AUSTRALIA

Australia Megascolides australis, and an equally large form in See also:

South See also:

AMERICA

America. (F. E.

End of Article: EARTHWORM

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