ONCE weighted down with antique icicles, silver snowflakes, Mexican peacocks and Philadelphia mummers, a Christmas tree takes on a life of its own. It shivers as you pass, quivers when you water it, shakes when the garbage trucks rumble by the house, trembles and settles down.

Then, in the middle of some frosty night, it falls over, its shiny balls cascading from its branches and bursting onto the rug in the darkened room, followed by a leaping troupe of jolly Santas, football players, ice skaters and dressed mice.

I'm sure there was a time -- was it when the baby was little? -- that the tree stayed up, because there were only a few dozen silver and blue balls back then, and some cherry-red apples made of cloth. That was the time of the wooden tree stand, nailed to the trunk in Christian symbolism.

But every year seems to require a bigger tree, in the name of upward mobility, and so brings the Christmas Eve cry of "Timber!" ever closer. One year, a drive to the hardware store yielded an enormous slice of plywood, soon to hold a peaceful little village -- imperiled by a Mount St. Helens flow of pine needles. (If it got too bad, the villagers could catch the train.)

That was the year of the red-and-green tree stand that looked like a dog's dish on four legs. To prop all four legs against the tree trunk, just so, was as impossible as solving a Rubik's cube -- which, by the way, makes a quaint ornament.

Another Christmas brought experiments in the two-nail theory of tree stability. 1. Drive two nails into the wall behind the tree, tie a string to one nail, run it in front of the tree and tie it to the other nail. After 15 minutes, do not stand in front of the tree. 2. For a tree displayed in a window, drive two nails into the window frame, etc., and, after 20 minutes, do not stand in front of the window.

Eventually we learn, and I became the proud owner of a sturdy metal reservoir the size of a small child's swimming pool, with clamps that screw into the trunk.

Last year some friends who for religious reasons do not have a tree came over to help trim ours. Not everyone is a Druid.

Everyone likes trimming trees. We even strung together popcorn garlands.

Two days later, an unexplained arboreal frisson undid their efforts. I redecorated the tree alone.

That was when I began to analyze the tree, turning it so that the natural curvature of the spine (they all have it) bent back toward the wall. That was the year I filled the metal reservoir with bricks for ballast.

Maybe this will be the year we make it through the holidays. Ah well, some listen for sleighbells, while others harken to a tinkling, creaking, whooshing sound in the living room.