Do you know that the word "gullible" does not appear in any English dictionary? I raise the point because the term is apposite in the context of those who have spent many years trying to find an explanation for the "corn circle" phenomenon.
It now turns out, according to a recent television programme, that the whole thing was started by one Mr Doug Bower, now aged 74, who constructed the first corn circle with a friend one night in 1978 as the pair made their way home from their local Wiltshire pub.
They used a few planks of wood, some lengths of rope and a ball of string, and the television programme showed exactly how they did it.
Corn circles have been something of a mystery ever since. Every year, as harvest time approaches in Wiltshire and Hampshire in the south of England, perfect circles of flattened stalks appear suddenly in the middle of large fields of ripening corn. Within these circles, which may be anything from 10 to 100 feet (3m to 30m) across, the flattened crop is arranged in a spiral flowing from the centre to the outer edge.
The circumference is geometrically perfect, forming an abrupt boundary between the flattened corn within and the vertical stalks of the unaffected crop. The circles usually occur singly, but complex examples are also seen from time to time.
Hundreds of examples of corn circles have been examined and carefully documented over the years, and many different explanations have been mooted. Many have liked to think of them as indications of a recent visit by a UFO which has felt inclined to leave a signature. One or two meteorologists, on the other hand, preferred to believe that the circles might have been caused by whirlwinds or vortices.
Such vortices, they say, could not be thermal in origin, because the circles occur in all types of weather conditions. But the theory is that they might be related to mechanical turbulence which occurs when the wind blows over hills or cliffs.
Alleged eyewitnesses have also reported that the appearance of the circles is sometimes accompanied by optical effects similar to those of ball lightning, which suggests to those who pursue these matters that static electricity may also play a part.
Believers of either kind are not convinced by Mr Bowen's story. Of course they accept that he was engaged in this activity some 20 years ago, and are prepared to admit that up to 80 per cent or so of the circles they have studied may well be the handiwork of like-minded pranksters.
But the remainder, they insist, have features which defy such a simple explanation.