Worm divides opinion

It’s the time of year when many gardeners are cleaning out their plots and digging them over. 

Digging inevitably exposes earthworms and sometimes the worms get damaged in the process. There is an old belief that if a worm gets cut in half by a spade it turns into two living worms. This belief was always ridiculed by biologists, at least until relatively recently when some impeccable scientific research proved that it does occasionally happen.

Twenty seven species of earthworm have been recorded in Ireland and it seems that each species has a different reaction to being cut in two. A worm’s body consists of a number of segments — the precise number depends on age and species but typically there are 20 to 50 of them. Most earthworm species appear to be able to survive having some of their rear segments removed. The rear end dies but the front end eventually regrows the missing segments, though sometimes the re-grown segments differ from the rest of the worm in either colour or diameter.