Since some members of the group don't like worms, there are no pictures!
The term worm is used in everyday language to describe many different distantly related animals that typically have a long cylindrical tube-like body and no limbs. Worms vary in size from microscopic to over 1 yard for marine bristle worms, 7 yards for the African giant earthworm and 60 yards for the marine bootlace worm, Lineus longissimus. Various types of worm are parasite, living inside the bodies of other animals. Free-living worm species do not live on land, but instead live in marine or freshwater environments, or underground by burrowing.
Earthworms in general have been around for 120 million years. They enrich and aerate the soil; Charles Darwin found that worms turn over the top six inches (15 cm) of topsoil every 20 years in a field near where he lived. They lack a brain in the sense of the vertebrate brain, but have nerve centers (called ganglia); they also lack eyes but can sense light with photoreceptors. Worms are hermaphrodites (both sexes in one animal) but can cross fertilize.
(The following was taken from here.)
More than 100 species of earthworms are found throughout much of the rest of the United States and were once native to the Great Lakes region, Hale said. But the creeping onset of giant glaciers from the north wiped out virtually all terrestrial life, including earthworms. That means that all the great northern forests -- from Canada down through Michigan, Wisconsin and Minnesota and into Ohio -- developed over thousands of years as worm-free ecosystems. The worms that survived the last ice age in the Central and Southern United States still haven't had enough time to crawl this far north (Northeast Ohio). At 5 yards a year, they could have traveled just over 30 miles in the last 11,000 years, scientists estimate. They are bad for sugar maples!
(The following was taken from here.)
Scientists have detected a number of drugs which could help protect against Alzheimer's disease, acting like statins for the brain. In experiments on worms, University of Cambridge researchers identified drugs which prevented the very first step towards brain cell death. ... The cancer drug bexarotene, for example, was found to stop the first step which leads to the death of brain cells in worms genetically programmed to develop Alzheimer's disease.
(Note - see above - worms do not have brains like ours, they have nerve centers, called ganglia.)
The word 'worm' used to mean dragon as in:
The Lambton Worm
One Sunday morn young Lambton went A-fishing' in the Wear;|
An' catched a fish upon he's heuk, He thowt leuk't varry queer.
But whatt'n a kind of fish it was, Young Lambton cuddent tell.
He waddn't fash te carry'd hyem, So he hoyed it doon a well.
cho: Whisht! Lads, haad yor gobs,
An Aa'll tell ye's aall an aaful story
Whisht! Lads, haad yor gobs,
An' Aa'll tell ye 'boot the worm.
Noo Lambton felt inclined te gan An' fight i' foreign wars.
He joined a troop o' Knights that cared For nowther woonds nor scars,
An' off he went te Palestine Where queer things him befel,
An' varry seun forgat aboot The queer worm i' the well.
But the worm got fat an' growed and' growed An' growed an aaful size;
He'd greet big teeth, a greet big gob, An' greet big goggle eyes.
An' when at neets he craaled aboot Te pick up bits o' news,
If he felt dry upon the road, He milked a dozen coos.
This feorful worm wad often feed On caalves an' lambs an' sheep,
An' swally little barins alive When they laid doon te sleep.
An' when he'd eaten aall he cud An' he had had he's fill,
He craaled away an' lapped he's tail Seven times roond Pensher Hill.
The news of this myest aaful worm An' his queer gannins on
Seun crossed the seas, gat te the ears Ov brave and' bowld Sor John.
So hyem he cam an' catched the beast An' cut 'im in twe haalves,
An' that seun stopped he's eatin' bairns, An' sheep an' lambs and caalves.
So noo ye knaa hoo aall the foaks On byeth sides ov the Wear
Lost lots o' sheep an' lots o' sleep An' leeved i' mortal feor.
So let's hev one te brave Sor John That kept the bairns frae harm,
Saved coos an' caalves by myekin' halves O' the famis Lambton Worm.