A few years ago, former California governor Gray Davis put a proposal on the table: He wanted to add six weeks to the school year for middle school students.

Whoa, can the governor do that? Isn't that like ... fooling with Mother Nature?

Actually, no, summer vacation is not ordained by nature. Summer, yes; summer vacation, no.

Right now, almost everywhere across the United States, the school year consists of 180 days of school followed by three months of summer vacation. This configuration is not built into the molecular structure of the universe, however. It's actually sort of arbitrary. It took shape in the mid-19th century to accommodate family farmers, so we're told. Back then family farms were so vital that if they didn't function, the country didn't eat. Schools were closed during the summer so that kids could help with farm chores.

I'm suspicious of this explanation. Granted, I'm no farmer, but I believe I could milk a chicken if I had to, and as far as I know, farmers have two big tasks: planting and harvesting. Isn't one accomplished in spring and the other in fall? How did summer sneak in there?

Could it be that the children of the 19th century pulled a little scam on their teachers? "Miss Appleby? I can't come to school when the days are warm and lazy because, um, I'm needed on the farm, see?" And did Miss Appleby, knowing only twice as much about farming as I do (which is still zero), swallow this line and let the kids go off to handle chores such as sliding down haystacks, climbing trees, and fishing?

Okay, maybe my scenario is far-fetched. But somehow, somewhere along the line, this romantic image of summer vacation got planted in our national psyche.

Almost as ubiquitous as summer vacation itself has been a contingent of Grinches advocating more school. In 1949 the Gallup Poll started checking the public pulse on this question. At first the public said no by a thumping margin of 67 to 26 percent. By the mid-1980s, however, yes and no were running neck and neck, and in 1989, for the first time, a thin majority (48 to 44 percent) favored adding more school days.