ON All Fools' Day we should be game for a laugh, but there are some people for whom jokes are no laughing matter. There are academics - would you believe? - who actually give lectures about laughter.

But then you know the definition of an academic: a person who, when you say to him: "Good morning", writes it down. Well, this year's BBC Reith lectures on Radio Four - Wednesdays at 8pm and repeated on Saturdays at 10.15pm to help us get to sleep - are being given by Vilanyanur Ramachandran on why we laugh.

Lord Reith (1889-1971), the first Director General of the BBC, was a Scotsman and a man renowned for his lack of any sense of the ridiculous. I don't know whether he would have been irritated or mystified to learn that lectures delivered in his memory should have any connection with humour. He was a Puritan and a disciplinarian, a man of whom it might have been said - as Winston Churchill said of Stafford Cripps - "There but for the grace of God goes God."

In 1929 Eric Gill sculpted a nude statue of Ariel, the sprite from The Tempest and adopted as the patron saint of broadcasting by the BBC. It was placed above the door of Broadcasting House where you can see it still. When Reith first saw the statue, he objected to the size of its penis. Gill refused to make any changes, so two Shakespearian scholars were appointed to decide on the size of what I suppose we must call Ariel's aerial. They concluded that Shakespeare had probably imagined Ariel as being about 13 years old. They called in a Harley Street doctor who agreed with the two Shakespeareans that, for such a young lad, the penis was indeed too big. So it was reduced.

Some of you will know that I'm a parson with two churches in the City of London and, I hope, a rudimentary sense of humour. On this great day of fools then, I'd like to repeat for you some of the jokes I've quoted from my pulpit over the years. Did you hear the tale about the vicar making his Sunday announcements? He said: "The ladies of the church have cast off clothing of every kind, and they can be seen in the church basement on Friday afternoon." Realising his bloomer, so to speak, he tried to cover his embarrassment but only made things worse when he added: "On Sunday a special collection will be taken to defray the expense of a new carpet. All those wishing to do something on the carpet, please come forward and get a piece of paper."

Then there was the church notice board that announced: "Next Sunday the vicar will preach his farewell sermon, after which the choir will sing 'Break Forth Into Joy'." And: "On Wednesday the Ladies Literary Society will meet. Mrs Smith will sing 'Put Me In My Little Bed' accompanied by the Rector. Next week it will be Easter Sunday, so Mrs White will come forward at the main service and lay an egg on the altar."

"The Christening Service will start with 'Little Drops of Water'. One of the men will start quietly and the rest of the congregation will join in." I think my favourite must be the notice board which said, during a time when the vicar was ill, "GOD IS GOOD. The Reverend Anderson is better." Lord Reith would not have approved.

* Peter Mullen is Rector of St Michael's, Cornhill, in the City of London, and Chaplain to the Stock Exchange.