|French websites about the April Fish include many old postcards. The top|
line on this one says "April 1" and the lower line says "Welcome my little messages!"
For a lot more of them see this: "Les Poissons d"Avril."
French candy and bakery shops get into this act by selling chocolates or pastries made to look like fish. Seeing displays of fish-shaped chocolate in the attractive windows of chocolate shops was another surprise for us when we were in France during the last weeks of March.
Here are examples of chocolate fish -- poissons d'Avril -- sold by leading, and expensive, French chocolate makers this year, and advertised on the web:
"From force of habit, people at first went on giving little presents on 1st April; then they gave presents designed to cause amusement, and to heighten the joke they started playing practical tricks. One of the most popular was to send a gullible person off to buy fresh fish, assuring him that the law [prohibiting fishing during the spring spawning season in late March-early April] had been changed... The victim would set off for the fish market, blissfully unaware that he had a paper fish pinned to his back so that everyone could see he had been fooled. Only a very stupid person would expect to buy 'April fish', and the joke ended with merry cries of 'Poisson d'Avril.'" (History of Food by Maguelonene Toussaint-Samat, p. 314)While the stories about the change to New Year's may be the most plausible explanation, they also raise a lot of questions, according to "The Origin of April Fool's Day."
I suspect that the April Fish custom itself is a kind of joke on us: we'll never know exactly how it came about.