Glossary
This is a useful glossary of terms which will be of use in the context of work associated with sustainable development, as well as with the care and maintenance of your school wormery.
In of itself, many of the terms referred to will help answer many frequently asked questions.
If we have not covered a specific question, please fell free to contact us at: info@thelearningworm.com.
Acid A liquid that tastes sour and smells somewhat sharp. Acids help dissolve rock and break down food. Vinegar is an acid. It is a normal product of decomposition. Redworms do best in a slightly acid (pH less than 7) environment. Below pH 5 can be toxic. Addition of pulverized egg shells and/or lime helps to neutralize acids in a wormery.
pH Scale 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
acid neutral alkaline
Aggregation Clustering, as when soil particles from granules that aid in aeration and or water penetration.
Aeration Exposure of a medium to air which allows exchanges of gases.
Aerobic Referring to the presence of free oxygen. Organisms that utilize oxygen to carry out life functions.
Air Mixture of atmospheric gases, including nitrogen, oxygen, carbon dioxide, and other gases in smaller quantities.
Albumin A protein in cocoons that serves as a food source from embryonic worms. Also found in egg white.
Alkaline Containing bases (hydroxides, carbonates) which neutralize acids to forms salts. See acid and pH.
Allolobophora caliginosa One of the early scientific names for the species of earthworm now known as Aporrectodea turgida, the pasture worm.
Allolobophora chlorotica Scientific name for green worm. It may look green, but also may appear yellow, pink or grey. Found in a wide variety of soil habitats, including gardens, fields, pastures, forest, clay, peat soils, lake shores and stream banks, and among organic debris. This species is generally a shallow burrower.
Anaerobic Referring to the absence of free oxygen. Organisms that can grow without oxygen present.
Animal A living being capable of sensing its environment and moving about, Animals live by eating the bodies of other organisms, whether plant or animal.
Annelid Term for a member of the Phylum Annelida containing segmented worms.
Anterior Towards the front. Apporectodea trapezoides Scientific name for southern worm, commonly found in earth around potted plants, gardens, fields, forest soils and banks of springs and streams. The worm lacks pigment. Its colour is often lighter behind the clitellum, darkening to brown, brownish, or reddish brown towards the posterior. Flattening of body neat posterior makes cross-section appear rectangular. Apporectodea turgida Scientific name for pasture worm, commonly found in gardens, fields, turf, compost and banks of springs and streams. This worm lacks pigment. The anterior may be flesh pink, the remaining segments pale grey. Aquatic Living in or upon water. Arctic Referring to the region around the North Pole. Bacteria Plural for bacterium, a one-celled organism which can be seen only with a microscope. Bacteria may be shaped like spheres, rods or twisted springs. Some bacteria cause decay; others may cause disease. Most bacteria are beneficial because they help recycle nutrients. Bar graph Presentation of data using columnar blocks. Also known as a histogram.
Barrier A geographic zone as an ocean, desert or glacier which would prevent the migration of an earthworm. Barriers may be different for other kinds of animals.
Bedding Moisture-retaining medium which provides a suitable environment for worms. Worm beddings are usually cellulose based, such as newspaper, corrugated cartons, leaf mould and compost.
Bio-degradable Capable of being broken down into simpler parts by living organisms.
Biologist A scientist who studies living things.
Biological control Management of pests within reasonable limits by encouraging natural predator/prey relationships and avoiding the use of toxic chemicals.
Blood A liquid medium circulating in the bodies of many animals. Blood carries food and oxygen to the tissues and carries waste products, including carbon dioxide, away from the tissues. Earthworms and humans both have a red, haemoglobin-based blood for oxygen transport.
Breathe To carry on activities to permit gas exchange, Humans and land dwelling vertebrates do this by expanding the lung cavity to draw air in, and reducing it to force air out. Worms conduct gas exchange through their moist skin but do not actually breathe.
Breeders Sexually mature worms as identified by clitellum.
Bristles Tiny rigid structures on most segments of earthworms which serve as brakes during movement. Known as setae, the patterns they form are a major distinguishing characteristic of earthworms.
Burrow Tunnel formed when an earthworm eats its way through soil, or pushes soil aside to form a place to live and move readily through the earth.
Calcium carbonate Used to reduce acidity in wormeries as well as in agricultural soils.
Carbon dioxide Gas produced by living organisms as they utilize food to provide energy. Also produced through the burning of fossil fuels.
Castings See worm castings.
Castings tea A solution containing nutrients which dissolve in water in the presence of worm castings.
Cellulose An inert compound containing carbon, hydrogen and oxygen; a component of worm beddings. Cellulose is found in wood, cotton, hemp and paper fibres.
Centipede A predator sometimes found in wormeries. Centipedes have more than eight jointed legs with one pair of legs attached to each of many segments.
Classify To organise materials, organisms, or information based upon a defined set of characteristics.
Clay As a soil separate, the mineral soil particles which are less than 0.002 mm in diameter. As a soil type, soil material that is 40% or more clay, less that 45% sand and less than 40% silt, Clay has smooth particles and feels sticky when wet. Clay absorbs moisture readily.
Climate The prevailing or average weather conditions of a place over a period of years.
Clitellum A swollen region containing gland cells which secrete the cocoon material. Sometimes called a girdle or band, it is present on sexually mature worms.
Cocoon Structure formed by the clitellum which protects embryonic worms until they hatch.
Cold-blooded Having blood that varies in temperature approximating that of the surrounding air, land or water. Fish, reptiles and worms are cold blooded animals.
Compost Biological reduction of organic waste to humus. Used to refer to both the process and the end product. One composts (verb) leaves, manure and garden residues to obtain compost (noun) which enhances soil texture and fertility when used in gardens.
Concentration In air or water, the strength or density of particles in a defined volume, The are we inhale has a higher concentration of oxygen molecules than carbon dioxide molecules.
Consumer An organism that feeds in other plants of materials.
Contract Action of muscle as it draws up, or gets shorter.
Culture To grow organisms under defined conditions. Also, the product of such activity, as a bacterial culture. Vermiculture is growing worms in culture.
Cyst A sac, usually spherical, surrounding an animal in a dormant state.
Decompose To decay, to rot; to break down into smaller particles.
Decomposer An organism that breaks down cells of dead plants and animals into simpler substances.
Decomposition The process of breaking down complex materials into simpler substances. End products of much biological decomposition are carbon dioxide and water.
Dendrobaena octaedra Scientific name of earthworm knows as the octagonal-tail worm. Found mostly in non-cultivated sites, such as in sod or moss on stream banks, under logs and leafy debris, or in cool moist ravines. Also found in dung and in soil rich in organic matter, A surface-dwelling species. Posterior is octagonal in cross-section.
Digestive tract The long tube where food is broken down into forms an animal can use. It begins at the mouth and ends at the anus.
Dissect To cut open in order to examine and identify internal structures.
Dissolve To go into solution.
Dorsal The top surface of an earthworm.
Earthworm A segmented worm of the annelid group which contains some 4,000 species. Most earthworms are terrestrial, i.e. they live in the ground. Earthworms have bristles known as setae which enable them to burrow in the soil. Earthworms help to aerate and enrich the soil.
Ecology The science of the interrelationships between living things and their surroundings.
Egg A female sex cell capable of developing into an organism when fertilized by a sperm.
Environment Surroundings, habitat.
Excrete To separate and to discharge waste. Experiment To conduct research by manipulating variables to answer specific questions expressed as statements known as hypotheses. Fertilise To supply nutrients to plants, or, to impregnate an egg. Food chain The sequence defined by who eats whom, starting with a producer (green plant). Food web The sequence defined by who eats whom, starting with producers and progressing through various levels of consumers, including decomposers and predators. Many organisms may be more than one level of consumer, depending upon whether they eat a plant, a micro organism which has consumed a plant, or an animal which ate the micro organism which ate the plant. A food web describes more complex linkages and interrelationships than a food chain. Fungi A large group of plants having no green colour and which reproduce by spores. The group includes mushrooms, toadstools, and microscopic plats including moulds and mildew. Fungus A member of the plant group Fungi. Gland A special type of tissue which produces secretions. Glands in worms' skin produce mucus. Gizzard Structure in anterior portion of digestive tract whose muscular contractions help grind food in the presence of grit. Hatchlings Worms as they emerge from a cocoon. Heart Muscular thickening in blood vessels whose valves control the direction of blood flow. Earthworms have several (commonly five pairs) of these blood vessels which connect the dorsal to the ventral blood vessels.
Heavy metal Dense metal such as cadmium, lead, copper and zinc which can be toxic in small concentrations. Build up of heavy metals in garden soil should be avoided.
Haemoglobin Iron-containing compound in blood responsible for its oxygen-carrying capacity.
Histogram A way of formulating data using columnar blocks. Also known as a bar graph.
Humus Complex, highly stable material formed during breakdown of organic matter.
Hydrated lime Calcium hydroxide. Do not use in wormeries. See lime.
Hypothesis A prediction of educated guess which is used to guide a scientist in designing an experiment.
Immigrate To move into a region.
Inoculate To provide an initial set of organisms for a new culture.
Larva Early form of any animal that changes structurally before becoming an adult. A caterpillar is an insect larva which becomes a moth or butterfly as an adult.
Leach To run water through a medium, causing soluble materials to dissolve and drain off.
Leaf mould Leaves in an advanced stage of decomposition.
Lime A calcium compound which helps reduce acidity in wormeries. Use calcium carbonate, ground limestone and eggs shells.
Litter (leaf) Organic material on forest floor containing leaves, twigs, decaying plants and associated organisms.
Loam A rich soil composed of clay, sand and some organic matter. Soil material that is 7% to 27% clay particles, 28% to 50% silt particles, and less than 52% sand particles. The organic matter acts like a sponge to hold water.
Lumbricidae Name of family group to which several red worm and night crawler species of earthworms belong.
Macro organisms Organisms large enough to see by naked eye.
Mate To join as a pair; to couple.
Membrane A tissue barrier capable of keeping some substances out and letting others in.
Micro organism Organism requiring magnification for observation.
Microscope, dissecting An instrument permitting magnification of organisms too small to see clearly with the naked eye, but too large for a light microscope.
Mineral A naturally occurring substance found on the earth which is neither animal nor plant. Minerals have distinct properties such as colour, hardness or texture.
Mineral soil Soil that is mainly mineral material and low in organic material. Its bulk density is greater than organic soil.
Mould A downy or furry growth on the surface of organic matter, caused by fungi, especially in the presence of dampness or decay.
Molecule The smallest particle of an element or compound that can exist by itself. Two atoms of oxygen make up a molecule of oxygen. Twp atoms of oxygen and one atom of carbon make up a molecule of carbon dioxide.
Muck Dark coloured, finely divided, well decomposed organic soil material mixed with mineral soil. The content of organic matter is more than 20%. Muck has the least amount of plant fibre to bulk density, and the lowest water content of all organic soil material when saturated with water.
Mucus A watery secretion, often thick and slippery, produced by gland cells. One function is to keep membranes moist.
Muscle Tissue made of specialised cells whose main function is to contract.
Nematodes Small (usually microscopic) roundworms with both free-living and parasitic forms. Not all nematodes are pests.
Night crawler A common name for the worm Lumbricus terrestris. Often called the Canadian night crawler in the United States or dew worm in Canada.
Nitrogen An odourless, colourless, tasteless gas which makes up nearly four fifths of the earth's atmosphere. When it combines with oxygen through the action of nitrogen-fixing bacteria, it can become incorporated into living tissue as a major part of protein.
Nocturnal Coming out at night.
Nourish To promote or sustain growth.
Oligochaeta Name of the class of annelids to which earthworms belong, characterised by having setae.
Optimal Most favourable conditions, such as for growth or for reproduction.
Organic matter Material which comes from something which was once alive.
Organism Any individual living thing.
Ovary Organ which produces eggs.
Overload To deposit more rubbish in a wormery than can be processed aerobically.
Oxygen Gaseous element in the earth's atmosphere essential to life as we know it.
Peat moss Sphagnum moss which is mined from bogs, dried, ground, and used as an organic matter.
Pest An organism which someone wants to get rid of.
Pesticide A chemical, synthetic or natural, which kills pests.
pH An expression for degree of acidity and alkalinity based upon the hydrogen ion concentration. The pH scale ranges from 0 to 14, pH of 7 being neutral, less than 7 acid, greater than 7 alkaline.
pH Scale 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
acid neutral alkaline
Plant An organism which is green at some stage in its life and which uses the energy from sunlight to produce its own food. Plants do not move about on their own. An oak tree is a plant.
Pollute To make foul or unclean, to contaminate.
Population The total number of individuals of a single species in a defined area.
Population density Number of specific organisms per unit area, e.g. 1000 worms per square metre.
Posterior Toward the rear, back or tail.
Potting soil A medium for potting plants.
Prostomium Fleshy lobe protruding above the mouth of an earthworm.
Protozoa Plural for protozoan, a one-celled organism belonging to the animal kingdom. Most protozoa live in water and can be seen only with a microscope. Some move by means of tiny hairs called cilia, others by a whip-like tail called a flagellum, and others by false feet called pseudopodia like amebas have.
Ratio A fixed relationship, expressed numerically, as in worm:rubbish ratio of 2:1.
Red worms A common name for Eisenia fetida and also Lumbricus rubellus. Eisenia fetida is a common worm used in vermicomposting.
Regenerate To replace lost parts.
Respire To exchange oxygen and carbon dioxide to maintain bodily processes.
Rubbish Refers specifically to discards which are theoretically dry, such as newspapers, boxes, cans, etc. The term is commonly used to indicate anything we throw away, including organics. With increasing emphasis on recycling, less material should be thrown away as rubbish.
Salt Salts are formed in wormeries as acids and bases combine, having been released from the decomposition of complex compounds.
Sand Loose, gritty particles of disintegrated rock ranging in size from 0.05 mm to 2.0 mm in diameter. Soil that is 85% or more sand and not more than 10% clay is classified as sandy soil. Sandy soil particles feel gritty. Water drains quickly through sandy soil.
Scientist A person who studies natural phenomena in a systematic manner.
Secrete To release a substance than fulfils some function within the organism.
Segments Numerous disc-shaped portions of an earthworm's body bounded anteriorly and posteriorly by membranes. People identify earthworms species by counting the number of segments anterior to the position of structures such as the clitellum, ovaries and testes. Segmentation is a characteristic of all annelids.
Setae Bristles on each segment used in locomotion.
Sexually mature Possessing a clitellum and capable of reproducing.
Silt As a soil separate, individual mineral particles that range in diameter from the upper limit of clay (0.002 mm) to the lower limit of very fine sand (0:05 mm). As a soil textural class, silt is 80% or more silt and less than 12% clay.
Slime Mucus secretion of earthworms which helps to keep skin moist so that gas exchange can take place.
Soil Soil is made up of mineral particles, organic matter, air and water. The mineral particles are called sand, clay or silt depending on their size. Sand has large particles and feels gritty. Clay has fine particles and feels sticky or slippery when wet. Silt particles range between clay and very fine sand. Soil types have differing amounts of each of these particles. Loam is a mixture of sandy soil, clay and organic matter. The organic matter acts like a sponge to hold water.
Sow bug A small crustacean with ten pairs of legs which breathes will gills and lives in organic litter.
Species Basic category of biological classification, characterised by individuals which can breed together.
Sperm Male sex cells.
Stress To produce conditions which cause an organism to experience discomfort.
Subsoil Mineral bearing soil located beneath humus-contained topsoil.
Taxonomist A scientist who specialises in classifying and naming organisms.
Terrestrial Living on land.
Toxic Poisonous, life threatening.
Turgid Swollen, distended, pressing out against sides.
Ventral Term for the underneath surface of an earthworm.
Vermicompost Mixture of partially decomposed organic waste, bedding, worm castings, compost worms and associated organisms. As a verb: to carry out composting with worms.
Vermiculture The raising of earthworms under controlled conditions.
Vibration A rapid, rhythmic motion back and forth. Earthworms are sensitive to vibration.
Warm-blooded Having warm blood and a constant natural body heat which is specific for each species. Mammals and birds are warm-blooded.
Worm bedding The medium, using cellulose-based, in which worms are raised in culture, such as shredded corrugated cartons, newspaper or leaf mould. Wormery Container deigned to accommodate a vermicomposting system. Worm casting Undigested material, soil and bacteria deposited through the anus. Worm manure.
