Just before I hit puberty, I think it was sixth grade, our gym teacher corralled us boys into the boys' locker room to see a movie describing the dramatic — not to say traumatic — changes that lay ahead. A man narrated the part about boys, a woman the part about girls. The man's voice was deep, reassuring, the sort you would choose to say, "We've had a report that there's a bomb in the building, but there's no need for alarm. Please exist the premises as quickly and quietly as possible. No shoving."

Besides the man's voice, the most memorable thing about the film was the scene in which the pubescent guy, who has suddenly developed an interest in girls, calls one on the phone and asks her out. She says yes, and after he hangs up, the guy leans back in his chair and places his hands behind his head in relaxed satisfaction, revealing dark circles on the underarms of his shirt. This gave the announcer the chance to remark that increased perspiration and body odor were among the secondary sex characteristics that we could look forward to.

I suppose "primary sex characteristics" means the simple fact of gender. That much is settled for Finian, and I am a long way from having to worry about the onset of secondary sex characteristics. What I've been noticing lately are those intermediate characteristics, those things that mark him as a boy and not a girl.

Writing about gender is tricky, but I think it can be done without making too man y claims about how things ought to be. Calvin Trillan, his memoir Family Man, writes of sending his daughter to a progressive nursery school where a percent "with emerging consciousness on matters of gender might ask if anything could be done about the boys monopolizing the block corner; based on my exposure to the parents of that school, I wrote a story about a feminist father who gives his little girl a catcher's mitt for Christmas only to have her plant a marigold in it. This is the fictional approach.

Garrison Keillor, in The Book of Guys, writes, "Girls had it better from the beginning, don't kid yourself. They were allowed to play in the house, where the books were and the adults, and boys were sent outdoors like livestock. Boys were noisy and rough, and girls were nice, so they got to stay and we had to go. Boys around in the yard with toy guys going kksshh-kksshh, fighting wars for made-up reasons and arguing about who was dead, while girls stayed inside and played with dolls, creating complex family groups and learning to solve problems through negotiation and role-playing. Which gender is better equipped, on the whole, to live an adult life, would you guess?" This is the humorous, self-deprecating approach.

I'm going to take the particular approach. What follows is a smattering of my evidence for Fin's boyness, based on my admittedly limited experience with my son and those small children I have met and watched in action. (Additional information has been provided by my wife and mother.)

Finian loves activity. My mother raised two boys. When she saw how six-week-old Fin kicked as he lay on his back, she said, "I had forgotten how active boys are. Monica and Kate [ my brother's daughters] never kicked that much." Since then, she has seen his boyness in his constant motion, his constant quest to get into things, to explore, to open, to unpack, to unscrew.

He loves balls. Soon after he was born, his great-grandparents set him a set of squeaky balls — a football, a baseball, and a basketball. They became highly prized, especially in the tub. Since then, the balls have accumulated, almost by themselves; a hi-bouncer, a beach ball, a Whiffle ball, a wobbly blue inflatable purchased on a whim at Wal-Mart, a stuffed cloth ball, a plastic football autographed by Otis Taylor of the Kansas City Chiefs (#84). The wobbly blue is his favorite. He wraps both arms around it and walks, waiting for me to nudge it free with my foot and play keep-away with him. A hopeful sign so far, he throws lefty.

He loves tools. Fin spends a fair amount of time in the kitchen with Deirdre, and so the tools he knows are kitchen tools: spoons, cups, spatulas, the Parmesan cheese grater, and so on. But he loves real tools best: hammers, screwdrivers, tape measures, the sorts of things Da is forever forbidding and taking away. Tools like that are good for banging dents in the soft wood of the coffee table, can't Da understand that? he consoles himself by smacking the floor with the broom handle and pulling the metal rod from the center of the rolling pin. Wood handle, metal tip — a fine hammer substitute. Let the banging begin.

Another lesson in boyishness from the kitchen, this one auditory: while he enjoys the crash of dropping pots, what fascinates him is the sound of motors. The Cuisinart and hand blender are good. The blender is better. The Kitchen Aid mixer is the best. And I have never seen him sit still with his eyes fixed in one place for as long as he does when the garbage truck clanks and clangs its way down the alley behind our house.

He loves guns. A warm evening inspired me to purchase a water pistol. My intention was to soak Deirdre, but Fin proved a far more agreeable victim. Each hit he sustained brought open-mouthed grins, and come to think of it, that open mouth made a good target. He liked this even better, to the point where he would charge me and wrap his mouth around the gun barrel in a silent plea to be shot.

The gun is broken, but he still enjoys waving it around — this is the way it is with boys and guns. When I was a boy, my parents, being modern and equipped with various theories, resolved never to buy me a toy gun. In this way, they hoped to triumph over generations of boyness and tame a nonviolent child.

So I found sticks with gunnish shapes and used them. I borrowed other kids' guns, then started making my own, down in the cellar. After years of primitive attempts, my efforts culminated in a sawed-off shotgun, like I'd seen on Miami Vice. A neighbor's dad — O happy child of such a father — carved the stock with a bandsaw, two pieces of copper pipe served as barrels. We didn't fight wars, a la Garrison Keillor. We played Hunter, in which two guys would hide, and three guys would hunt them down. I still turned out pretty nonviolent, perhaps because I was never allowed to point guns at adults.

Fin has an adventurous streak, more so than most girls we know. Once, Deirdre let him wander in an airport, hoping he would wear himself out for the coming flight. What surprised her was how far he was willing to go without looking back. The only thing that kept him from plunging headlong into the anonymous throng was a steady supply of pizza, carefully doled out by mama in bite-sized chunks. Fin ran until his mouth was empty; then returned, reeled in by his tongue.

When he came home, he brought his wandering ways with him. now and then, he leaves the bed during our morning coffee and toddles down the hall. Parent may be a voice of comfort and security, but they are also a source of discipline and denial. With us planted safely in bed, he is free to abscond with, say, the portable phone On one of my recovery missions, I arrived in the living room just in time to see him hoofing it toward the family room, phone tucked over his shoulder.

While he plays in our yard, he eases himself toward the sidewalk, sidles around the hedge, and dashes for the wide open yonder when we come to collect him. He tries to prevent this by stepping out while we are still in the kitchen, then sliding the screen door shut behind him, waving and saying, "Bye-bye." His meaning is clear: "I'm going now; you stay here."